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Lipase and photodecarboxylase coexpression: A potential strategy for alkane-based biodiesel production from natural triglycerides
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作者 Yong-Yi Zeng Xin-Yi Xu +4 位作者 Jin-Xuan Xie Wen-Li Chen Lan Liu Xin-Jian Yin Bi-Shuang Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期238-246,共9页
Alkane-based biodiesel is considered the next generation of biodiesel owing to its potential environmental benefits and the fact that it exhibits much higher specific caloric values than traditional biodiesel.However,... Alkane-based biodiesel is considered the next generation of biodiesel owing to its potential environmental benefits and the fact that it exhibits much higher specific caloric values than traditional biodiesel.However,the formidable obstacle impeding the commercialization of this cutting-edge fuel alternative lies in the cost associated with its production.In this study,an engineered strain Escherichia coli(E.coli)showcasing harmonized coexpression of a lipase(from Thermomyces lanuginosus lipase,TLL)and a fatty acid photodecarboxylase(from Chlorella variabilis,CvFAP)was first constructed to transform triglycerides into alkanes.The potential of E.coli BL21(DE3)/pRSFDuet-1-TLL-CvFAP for alkane synthesis was evaluated with tripalmitin as a model substrate under various process conditions.Following a comprehensive examination of the reaction parameters,the scope of the biotransformation was expanded to‘real’substrates(vegetable oils).The results showed that bioderived oils can be transformed into alkanes with high yields(0.80-10.20 mmol·L^(-1))under mild conditions(35℃,pH 8.0,and 36 h)and blue light illumination.The selected processes were performed on an increased lab scale(up to 100 ml)with up to 24.77 mmol·L^(-1) tripalmitin,leading to a yield of 18.89 mmol·L^(-1) pentadecane.With the employment of a method for efficiently producing alkanes under mild conditions and a simple procedure to isolate alkanes from the reaction system,the utilization of sustainable biomass as a fundamental feedstock emerges as the primary solution to lower the cost of alkane-based biodiesel.Thus,this study proposes a readily implementable and highly effective approach for alkane-based biodiesel production. 展开更多
关键词 Alkane-based biodiesel Renewable biomass Co-overexpression lipase Photodecarboxylase
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Conjugation of Candida rugosa lipase with hydrophobic polymer improves esterification activity of vitamin E in nonaqueous solvent
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作者 Xiaoyun Hou Qinghong Shi 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第10期182-191,共10页
We described a novel polymer-lipase conjugate for high-efficient esterification of vitamin E using vitamin E and succinic anhydride as the substrates in nonaqueous media.In this work,the monomer,N-isopropylacrylamide(... We described a novel polymer-lipase conjugate for high-efficient esterification of vitamin E using vitamin E and succinic anhydride as the substrates in nonaqueous media.In this work,the monomer,N-isopropylacrylamide(NIPAM),was grafted onto Candida rugosa lipase(CRL)to synthesize poly(NIPAM)(pNIPAM)-CRL conjugate by atom transfer radical polymerization via the initiator coupled on the surface of CRL.The result showed that the catalytic efficiencies of pNIPAM-CRL conjugates(19.5-30.3 L·s^(-1)·mmol^(-1))were at least 7 times higher than that of free CRL(2.36 L·s^(-1)·mmol^(-1))in DMSO.It was attributed to a significant increase in Kcat of the conjugates in nonaqueous media.The synthesis catalyzed by pNIPAM-CRL co njugates was influenced by the length and density of the grafted polymer,water content,solvent polarity and molar ratio of the substrates.In the optimal synthesis,the reaction time was shortened at least 7 times,and yields of vitamin E succinate by pNIPAM-g-CRL and free CRL were obtained to be 75.4%and 6.6%at 55℃after the reaction for 1.5 h.The result argued that conjugation with pNIPAM induced conformational change of the lid on CRL based on hydrophobic interaction,thus providing a higher possibility of catalysis-favorable conformation on CRL in nonaqueous media.Moreover,pNIPAM conjugation improved the thermal stability of CRL greatly,and the stability improved further with an increase of chain length of pNIPAM.At the optimal reaction conditions(55℃and 1.5 h),pNIPAM-g-CRL also exhibited good reusability in the enzymatic synthesis of vitamin E succinate and kept~70%of its catalytic activity after ten consecutive cycles.The research demonstrated that pNIPAM-g-CRL was a more competitive biocatalyst in the enzymatic synthesis of vitamin E succinate and exhibited good application potential under harsh industrial conditions. 展开更多
关键词 Candida rugosa lipase POLYMERS BIOCATALYSIS ESTERIFICATION Vitamin E succi
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Changes in Lipoprotein Lipase in the Heart Following Diabetes Onset
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作者 Chae Syng Lee Yajie Zhai Brian Rodrigues 《Engineering》 SCIE EI CAS CSCD 2023年第1期19-25,共7页
Due to its constant pumping and contraction, the heart requires a substantial amount of energy, with fatty acids (FAs) providing a major part of its adenosine triphosphate (ATP). However, the heart is incapable of mak... Due to its constant pumping and contraction, the heart requires a substantial amount of energy, with fatty acids (FAs) providing a major part of its adenosine triphosphate (ATP). However, the heart is incapable of making this substrate and attains its FAs from multiple sources, including the action of lipoprotein lipase (LPL). LPL is produced in cardiomyocytes and subsequently secreted to its heparan sulfate proteoglycan (HSPG) binding sites on the plasma membrane. To then move LPL to the endothelial cell (EC) lumen, glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) attaches to interstitial LPL and transfers it to the vascular lumen, where the LPL is ready to perform its function of breaking down circulating triglycerides (TG) into FAs. The endo-β-glucuronidase heparanase (Hpa) is unique in that it is the only known mammalian enzyme to cleave heparan sulfate (HS), thereby promoting the abovementioned release of LPL from the cardiomyocyte HSPG. In diabetes, it has been suggested that changes in how the heart generates energy are responsible for the development of diabetic cardiomyopathy (DCM). Following moderate diabetes, with the reduction in glucose utilization, the heart increases its LPL activity at the vascular lumen due to an increase in Hpa action. Although this adaptation might be beneficial to compensate for the underutilization of glucose by the heart, it is toxic over the long term, as harmful lipid metabolite accumulation, along with augmented FA oxidation and thus oxidative stress, leads to cell death. This coincides with the loss of a cardioprotective growth factor—namely, vascular endothelial growth factor B (VEGFB). This review discusses interconnections between Hpa, LPL, and VEGFB and their potential implications in DCM. Given that mechanism-based therapeutic care for DCM is unavailable, understanding the pathology of this cardiomyopathy, along with the contribution of LPL, will help us advance its clinical management. 展开更多
关键词 Cardiac metabolism Lipopr otein lipase HEPARANASE Vascular endothelial growth factor Diabetic car diomyopathy
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Novel Lipase from Golden Pompano(Trachinotus ovatus)Viscera:Purification,Characterization,and Application in the Concentrating of n-3 Polyunsaturated Fatty Acids
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作者 LIU Hongxia LIU Shucheng +4 位作者 ZHANG Xueying LIU Zhongyuan LI Chuan XIA Guanghua SHEN Xuanri 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第2期501-508,共8页
Lipases have been widely applied in a variety of industrial fields,such as food,pharmaceuticals,biofuels,and biotechnology.Recent years have witnessed a great interest in modifying lipids for the production of triacyl... Lipases have been widely applied in a variety of industrial fields,such as food,pharmaceuticals,biofuels,and biotechnology.Recent years have witnessed a great interest in modifying lipids for the production of triacylglycerols enriched with n-3 polyunsaturated fatty acids(PUFAs).Here,a novel salt-tolerant,organic solvent-stable,and bile salt-activated lipase was purified from golden pompano(Trachinotus ovatus)viscera,which was named as golden pompano lipase(GPL).GPL had a specific activity of 57.2U mg^(-1)with an estimated molecular weight of 14 k Da,exhibited optimal activity at 40℃a nd pH 8.0,and showed K_(m)and V_(max)of 40.16μmol L^(-1)and 769.23μmol L^(-1)min^(-1),respectively.GPL activity was enhanced by Mn^(2+)and sodium deoxycholate.It was active in organic solvents,including methanol,ethanol,chloroform,and hexane.GPL also showed a good salinity tolerance of up to 1 mol L^(-1).n-3PUFA enrichment in the glyceride fraction of golden pompano oil was performed by GPL-catalyzed hydrolysis and yielded a total PUFA concentration of 56.99%.EPA,DHA,and DPA were enriched by 10.4-,3.2-,and 1.8-fold of their initial levels,respectively.This study recognized the industrial applicability of GPL to prepare enriched C_(20-22)n-3 PUFA. 展开更多
关键词 golden pompano lipase CHARACTERIZATION n-3 polyunsaturated fatty acids
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Bound lipase:an important form of lipase in rice bran (Oryza sativa)
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作者 Chengwei Yu Bin Peng +1 位作者 Ting Luo Zeyuan Deng 《Food Science and Human Wellness》 SCIE CSCD 2023年第5期1779-1787,共9页
Rice bran residue possessed a steady lipase activity((26.68 ± 3.69)%)after its endogenous lipase was extracted continuously by phosphate buffer solution(PBS)for 24 h. T herefore, the aim of this research was to e... Rice bran residue possessed a steady lipase activity((26.68 ± 3.69)%)after its endogenous lipase was extracted continuously by phosphate buffer solution(PBS)for 24 h. T herefore, the aim of this research was to explore whether there exist any bound lipases in rice bran(Oryza sativa). Three physical treatments(grinding, homogenizing and ultrasound crush)and 6 enzymatic treatments(cellulase, hemicellulase, pectinase, complex cellulase, glucoamylase and α-amylase)were applied to rice bran in order to investigate this bound lipase. The relative catalytic activities of extraction supernatant and residue for pectinase group were(437.63 ± 22.54)% and(159.26 ± 2.12)%, respectively, which were significantly higher(P < 0.05)than other groups. This phenomenon demonstrated that lipase was the most likely to combine with pectin. Molecular simulation proved that pectin could combine with two rice bran lipases(lipase 315 and lipase 308)and cover the catalytic centers so as to prevent the lipases from encountering the substrate and inhibiting their catalytic activities. During combination, pectin could make the lipases more compact and reduce the solvent accessible surface area of lipases, which would make the lipases inactive to molecular interaction. In summary, part of rice bran lipase was proved to exist in bound form and combined with the pectin. 展开更多
关键词 Rice bran Bound lipase PECTIN Catalytic activity
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Facile Preparation of Dopamine-Modified Magnetic Zinc Ferrite Immobilized Lipase for Highly Efficient Synthesis of OPO Functional Lipid
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作者 Xue Huang Zeyu Chen +1 位作者 Ruizhao Yang Guangzhu Feng 《Journal of Renewable Materials》 SCIE EI 2023年第5期2301-2319,共19页
1,3-Dioleoyl-2-palmitoylglycerol(OPO)has been a hotspot of functional oils research in recent years,but due to the high cost of sn-1,3 specific lipase in enzymatic synthesis and the lack of biocatalyst stability,large... 1,3-Dioleoyl-2-palmitoylglycerol(OPO)has been a hotspot of functional oils research in recent years,but due to the high cost of sn-1,3 specific lipase in enzymatic synthesis and the lack of biocatalyst stability,large-scale industrial application is difficult.In this study,the prepared magnetic ZnFe_(2)O_(4) was functionalized with dopamine to obtain ZnFe_(2)O_(4)@PDA,and the nano-biocatalyst ZnFe_(2)O_(4)@PDA@RML was prepared by immobilizing sn-1,3 specific lipase of Rhizomucor miehei lipase(RML)via a cross-linking method.The existence of RML on ZnFe_(2)O_(4)@PDA was confirmed by XRD,FTIR,SEM,and TEM.This strategy proved to be simple and effective because the lipase immobilized on magnetic nanoparticles could be quickly recovered using external magnets,enabling reuse of the lipase.The activity,adaptability to a high temperature,pH value,and operational stability of immobilized RML were superior to those of free RML.After optimizing the synthesis conditions,the OPO yield was 42.78%,and the proportion of PA at the sn-2 position(PA-Sn2)was 54.63%.After the first four cycles,the activity of ZnFe_(2)O_(4)@PDA@RML was not significantly affected.The magnetically immobilized lipase has good thermal stability,long-term storage stability,reusability,and high catalytic activity.It can be used as a green and efficient biocatalyst to synthesize the OPO functional lipid. 展开更多
关键词 POLYDOPAMINE immobilized lipase 1 3-dioleoyl-2-palmitoylglycerol functional lipid
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Encapsulation of lipases on coordination polymers and their catalytic performance in glycerolysis and esterification
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作者 Can Zeng Nanjing Zhong 《Grain & Oil Science and Technology》 CAS 2023年第3期113-119,共7页
In this study,lipases of CALB(Candida antarctica lipase B),TLL(Thermomyces lanuginosa lipase),RML(Rhizomucor miehei lipase),CALA(Candida antarctica lipase A)and LU(Lecitase?Ultra)were encapsulated into the nucleotideh... In this study,lipases of CALB(Candida antarctica lipase B),TLL(Thermomyces lanuginosa lipase),RML(Rhizomucor miehei lipase),CALA(Candida antarctica lipase A)and LU(Lecitase?Ultra)were encapsulated into the nucleotidehybrid metal coordination polymers(CPs)for diacylglyerols(DAG)preparation.Guanosine 5'-monophosphate(GMP)and adenosine 5'-monophosphate(AMP)were used as coordinating molecules,and metal ions of Fe^(3+),Ba^(2+),Mn^(2+),Ni^(2+)and Cr^(3+)were applied to prepare matrix.Results indicated that,besides Ba^(2+)with AMP,all other metal ions can coordinate with AMP and GMP to generate CPs.In addition,the AMP/Ni was amorphous when standing temperature was 4℃,while it was crystalline when standing temperature was from 30 to 180℃.DAG content from 47.55%to 64.99%was obtained from glycerolysis by CALB@GMP/Ba,RML@GMP/Ba,TLL@GMP/Ba,RML@GMP/Mn and TLL@GMP/Mn.Additionally,CALB@GMP/Fe showed selectivity towards DAG formation in the esterification and DAG content up to 61.88%was obtained. 展开更多
关键词 lipase Coordination polymers ENCAPSULATION GLYCEROLYSIS ESTERIFICATION
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铜绿假单胞菌脂肪酶Lipase基因的原核表达(英文) 被引量:7
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作者 张煜星 武寒雪 +2 位作者 祝建波 刘焕 周鹏 《Agricultural Science & Technology》 CAS 2008年第5期59-62,共4页
[Objective] The aim of this study was to investigate the prokaryotic expression of pseudomonas aeruginosa Lipase gene.[Method]Lipase gene was amplified by PCR from the genome DNA of pseudomonas aeruginosa,and its nucl... [Objective] The aim of this study was to investigate the prokaryotic expression of pseudomonas aeruginosa Lipase gene.[Method]Lipase gene was amplified by PCR from the genome DNA of pseudomonas aeruginosa,and its nucleotide sequence was determined.The prokaryotic expression vector of Lipase gene was constructed by the gene recombination technique.The protein expression was induced for 4 hours by IPTG with the final concentration of 1.0 mmol/L,and then SDS-PAGE electrophoresis was analyzed.[Result]The sequence of mature peptides in Lipase gene cloned from pseudomonas aeruginosa had a 99.36% homology with that of pseudomonas aeruginosa lipase submitted in NCBI,so the prokaryotic expression vector of Lipase gene pET32a-Lip was successfully constructed.Furthermore,the results of SDS-PAGE electrophoresis showed that the target gene was expressed highly and effectively.[Conclusion]The cloned pseudomonas aeruginosa lipase with its signal peptide could be normally expressed in E.coli and also used for further study. 展开更多
关键词 PSEUDOMONAS AERUGINOSA lipase PROKARYOTIC expression
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Fermentation Performance and Characterization of Cold-Adapted Lipase Produced with Pseudomonas Lip35 被引量:2
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作者 YU Hong-wei HAN Jun LI Ning QIE Xiao-sha JIAYing-min 《Agricultural Sciences in China》 CAS CSCD 2009年第8期956-962,共7页
Strain of Pseudomonas Lip35 producing lipase was isolated in a refrigerator. Lipase production and characterization of this strain were investigated under different conditions. The Pseudomonas was cultivated in shakin... Strain of Pseudomonas Lip35 producing lipase was isolated in a refrigerator. Lipase production and characterization of this strain were investigated under different conditions. The Pseudomonas was cultivated in shaking flasks in a fermentation medium in various nutritional and physical environments. Lipase production has been influenced by the presence of yeast-extract, soybean powder, NaCI, and Tween-80. Maximum lipase productivity was obtained when the physical environment of the fermentation medium was optimal for 67 h. The production of lipase reached 58.9 U·mL^-1. The lipase of Pseudomonas Lip35 can be considered to be inducible, but the inducer had little influence on the production of lipase. The lipase was characterized and showed high lipolytic activity from pH 7.5-8.0. The optimum temperature was observed at 20℃ and the thermal inactivation of lipase was obvious at 60℃. The lipase activity was inhibited by K+, stimulated by Ca^2+, and thermostability decreased in the presence of Ca^2+, therefore the lipase was Ca^2+ -dependent cold-adapted enzyme. 展开更多
关键词 cold-adapted lipase fermentation optimization lipase characterization Pseudomonas Lip35
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Two rare cases of benign hyperlipasemia in children
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作者 Elena Lionetti Ruggiero Francavilla +4 位作者 Salvatore Leonardi Stefania Tomarchio Alessia Gennaro Chiara Franzonello Mario La Rosa 《World Journal of Clinical Cases》 SCIE 2014年第1期16-19,共4页
Gullo's syndrome is a newly identified condition characterized by a chronic elevation of pancreatic amylase and/or lipase in the absence of pancreatic disease. Until now, only one case of benign isolated hyperlipa... Gullo's syndrome is a newly identified condition characterized by a chronic elevation of pancreatic amylase and/or lipase in the absence of pancreatic disease. Until now, only one case of benign isolated hyperlipasemia in children has been recorded. We describe two children with benign and not familial increase of serum lipase. Case 1: a six year old girl presented with occasional discovery of serum lipase elevation. Medical history was silent for pancreatic hyperenzymemia. The screening for possible causes for elevated lipase(genetic, autoimmune and infectious diseases) was normal. The serum lipase increased three fold over the upper limit(193 U/L; reference range 0-60 U/L), with daily fluctuation of values. Both ultrasound scan and magnetic resonance imaging were normal. The genetic mutation associated with chronic pancreatitis was negative. We followed up this patient for two years with blood tests every six months and she did not show any signs or symptoms of pancreatic disease, except for the high level of lipase serum. Case 2: an eight year old girl complained of nausea, vomiting and severe abdominal pain in theepigastric region after eating for the last two weeks. Full blood count, electrolytes, C-reactive protein, liver and renal function were normal. Serum lipase was 96 U/L(reference range 0-60 U/L). The screening for the possible causes of pancreatic disease was negative. Endoscopy of the upper gastrointestinal tract, ultrasound, computed tomography scan and magnetic resonance imaging were normal. One year after the presentation of the symptoms, the patient became asymptomatic although the level of serum lipase continued to be high. 展开更多
关键词 AMYLASE lipase PANCREATIC hyperenzymemia Gullo’s SYNDROME BENIGN hyperlipasemia
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Study on Immobilized Lipase Catalyzed Transesterification Reaction of Tung Oil 被引量:8
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作者 XU Gui-zhuan ZHANG Bai-liang LIU Sheng-yong YUE Jian-zhi 《Agricultural Sciences in China》 CAS CSCD 2006年第11期859-864,共6页
The transesterification reaction conditions of tung oil with methanol have been studied in this article, with immobilized lipase NOVO435 as catalyst. The response surface methodology was used to optimize the transeste... The transesterification reaction conditions of tung oil with methanol have been studied in this article, with immobilized lipase NOVO435 as catalyst. The response surface methodology was used to optimize the transesterification reaction of tung oil in a nonsolvent system. The optimal conditions were rotation rate 200 r/min, molar ratio of methanol to oil 2.2: l, reaction temperature 43℃, and the catalyst amount 14% (based on the weight of oil). After reacting for 18 h, 67.5% of the oil was converted to its corresponding methyl esters (the theoretical ester conversion was 73.3%). The lipase was washed by organic solvents after each reaction and was reused again. The esters conversion of tung oil was decreased by 6% after the lipase was reused for 120 h. The theoretical amount of methanol was added in two steps, 85% ester conversion was obtained after 36 h of reaction (theoretical ester conversion was 100%). The molar ratio of methanol to oil, the catalyst amount, the reaction temperature, and reaction time were all highly significant factors, and there was a relative significant interaction between every two factors. 展开更多
关键词 NONSOLVENT TRANSESTERIFICATION BIODIESEL lipase tung oil
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Kinetics of the Esterification Reaction Catalyzed by Lipase in W/O Microemulsions of Alkyl Polyglucoside 被引量:8
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作者 JinLingCHAI ShouQingWANG +2 位作者 GanZuoLI QingXU YanHongGAO 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第6期699-702,共4页
A novel kinetic mechanism of esterification reaction of 1-hexanoic acid with 1-butanol, catalyzed by lipase, was studied in water-in-oil microemulsions. The microemulsions were formed by alkyl polyglucoside C10G1.54/1... A novel kinetic mechanism of esterification reaction of 1-hexanoic acid with 1-butanol, catalyzed by lipase, was studied in water-in-oil microemulsions. The microemulsions were formed by alkyl polyglucoside C10G1.54/1-butanol / cyclohexane/phosphate buffer solution. The result shows that when the ratio of mol concentration of 1-butanol to 1-hexanoic acid is about 3.0, the initial rate V0 get the maximum values. This phenomenon was explained by the modified fishlike phase diagrams. 展开更多
关键词 Alkyl polyglucoside W/O microemulsion lipase catalysis kinetics.
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Zwitterionic polymer-coated porous poly(vinyl acetate–divinyl benzene)microsphere: A new support for enhanced performance of immobilized lipase 被引量:4
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作者 Yifeng Li Chunyu Zhang Yan Sun 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第1期242-248,共7页
Enzyme immobilization has attracted great attention for improving the performance of enzymes in industrial applications.This work was designed to create a new support for Candida rugosa lipase(CRL)immobilization.A por... Enzyme immobilization has attracted great attention for improving the performance of enzymes in industrial applications.This work was designed to create a new support for Candida rugosa lipase(CRL)immobilization.A porous poly(vinyl acetate–divinyl benzene)microsphere coated by a zwitterionic polymer,poly(maleic anhydride-alt-1-octadecene)and N,N-dimethylethylenediamine derivative,was developed for CRL immobilization via hydrophobic binding.The catalytic activity,reaction kinetics,stabilities and reusability of the immobilized CRL were investigated.It demonstrated the success of the zwitterionic polymer coating and subsequent CRL immobilization on the porous microsphere.The immobilized lipase(p2-MS-CRL)reached27.6 mg·g^-1 dry carrier and displayed a specific activity 1.5 times higher than free CRL.The increase of Vmax and decrease of Kmwere also observed,indicating the improvement of catalytic activity and enzyme-substrate affinity of the immobilized lipase.Besides,p2-MS-CRL exhibited significantly enhanced thermal stability and pH tolerance.The improved performance was considered due to the interfacial activation regulated by the hydrophobic interaction and stabilization effect arisen by the zwitterionic polymer coating.This study has thus proved the advantages of the zwitterionic polymer-coated porous carrier for lipase immobilization and its potential for further development in various enzyme immobilizations. 展开更多
关键词 BIOCATALYSIS lipase immobilization ZWITTERIONIC polymer HYDROPHOBIC binding Interfacial activation Stabilization
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Identification of five strains of antarctic bacteria producing low-temperature lipase 被引量:6
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作者 YANGXiuxia LINXuezheng +2 位作者 BIANJi SUNXiuqin HUANGXiaohang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2004年第4期717-723,共7页
Five strains of antarctic bacteria producing extracellular low-temperature lipase are screened from seawater collectedby CTD during the Chinese 18th Antarctic Scientific Expedition. Their phylogenetic positions on the... Five strains of antarctic bacteria producing extracellular low-temperature lipase are screened from seawater collectedby CTD during the Chinese 18th Antarctic Scientific Expedition. Their phylogenetic positions on the basis ofamplification, comparison and analysis of almost complete 16S rDNA sequence are determined by neighbor-joininganalysis. Phylogenetic analysis indicates that all of these five strains belong to g-proteobacteria. The strains 11102 and 92 are classified as genus Pseudoalteromonas sp. and genus Psychrobacter sp. respectively. The strains 25101, 2221 and 1281 are classified as genus Moritella sp. 展开更多
关键词 antarctic bacteria low-temperature lipase 16S rDNA phylogenetic analysis
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Fabrication and characterization of epoxylated zwitterionic copolymergrafted silica nanoparticle as a new support for lipase immobilization 被引量:4
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作者 Ning Chen Chunyu Zhang +1 位作者 Xiaoyan Dong Yan Sun 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第4期1129-1135,共7页
Our previous work proved that the thermal stability of Candida rugosa lipase(CRL)immobilized on zwitterionic polymer(poly(carboxybetaine methacrylate))grafted silica nanoparticle(SNP)was much higher than that on poly(... Our previous work proved that the thermal stability of Candida rugosa lipase(CRL)immobilized on zwitterionic polymer(poly(carboxybetaine methacrylate))grafted silica nanoparticle(SNP)was much higher than that on poly(glycidyl methecrylate)(pGMA)grafted SNP,while the latter showed significantly increased activity.Inspired by the research,we have herein proposed to synthesize copolymers of zwitterionic sulfobetaine methacrylate(SBMA)and GMA for CRL immobilization.The copolymers were grafted onto SNP surface at three GMA/SBMA(G/S)molar ratios(G100/S0,G50/S50,G10/S90),followed by the covalent coupling of CRL to the surface copolymers.The immobilized CRLs on the corresponding supports were denoted as p(G100-S0)-CRL,p(G50-S50)-CRL and p(G10-S90)-CRL.The enzyme loading increased with the increase of GMA content in the copolymer,while the activity varied with the grafted copolymer composition.Kinetic study proved the improvement of enzyme-substrate affinity after immobilization.In comparison to p(G100-S0)-CRL,p(G50-S50)-CRL and p(G10-S90)-CRL presented remarkably enhanced thermal stability and pH tolerance,and p(G10-S90)-CRL showed the highest stability.These results suggest that the copolymer design is promising for development as a versatile platform for enzyme immobilization. 展开更多
关键词 lipase IMMOBILIZATION Zwitterionic copolymer Interfacial activation STABILIZATION
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Impact of serum levels of lipoprotein lipase, hepatic lipase, and endothelial lipase on the progression of coronary artery disease 被引量:6
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作者 Hui Han Daopeng Dai +4 位作者 Wencheng Wang Jinzhou Zhu Zhengbin Zhu Lin Lu Ruiyan Zhang 《Journal of Interventional Medicine》 2019年第1期16-20,共5页
Purpose: The purpose of this study was to investigate the relationship between serum levels of lipoprotein lipase(LPL), hepatic lipase(HL), and endothelial lipase(EL) and the progression of coronary artery disease(CAD... Purpose: The purpose of this study was to investigate the relationship between serum levels of lipoprotein lipase(LPL), hepatic lipase(HL), and endothelial lipase(EL) and the progression of coronary artery disease(CAD).Materials and methods: According to the inclusion criteria, exclusion criteria, diagnostic criteria, angiography results, and the random matching scheme, the enrolled patients were divided into the following two groups: the progression-free group(n ? 47) and the progression group(n ? 15). The baseline characteristics and various biochemical parameters were obtained from the medical records and medical history. Serum LPL, HL, and EL levels were detected by ELISA. The correlation between serum LPL, HL, and EL levels and coronary lesions was statistically analyzed with SPSS software.Results: Significant differences were observed in serum levels of HL and EL between the progression-free group and the progression group(HL, 75.5 ? 39.2 ng/mL vs. 125.1 ? 42.1 ng/mL, P < 0.05;EL, 139.2 ? 59.6 pg/mL vs.175.1 ? 40.1 pg/mL, P < 0.05), while the difference in the LPL level was not significant(P > 0.05). Receiver operating characteristic curve(ROC) analysis showed that the area under the curve(AUC) values of LPL, HL, and EL were 0.506(95% CI: 0.369–0.642, P ? 0.9470), 0.792(95% CI: 0.664–0.888, P < 0.0001), and 0.693(95% CI:0.553–0.811, P ? 0.0095), respectively. Additionally, logistic regression analysis showed that the serum level of HL was an independent risk factor for coronary artery lesion progression.Conclusion: Serum levels of EL and HL, but not the serum level of LPL, were positively correlated with the progression of CAD. The serum level of HL was an independent risk factor for the progression of CAD, while the serum level of EL or LPL was not an independent risk factor for the progression of CAD. For the diagnosis of CAD progression, the serum level of HL was better than the serum level of EL or LPL. 展开更多
关键词 LIPOPROTEIN lipase Hepatic lipase Endothelial lipase In SITU coronary artery PLAQUE PROGRESSION Atherosclerosis
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Lipase and pancreatic amylase activities in diagnosis of acute pancreatitis in patients with hyperamylasemia 被引量:6
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作者 Rong-Wei Yang, Zhe-Xin Shao, Yi-Yi Chen, Zhou Yin and Wen-Juan Wang Clinical Laboratory, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China and Clinical Laboratory, Zhejiang Xinhua Hospital, Hangzhou 310003 , China 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2005年第4期600-603,共4页
BACKGROUND: Measurement of total serum amylase (AMY) is the most widely used biochemical test for the diagnosis of acute pancreatitis, but it is commonly considered a nonspecific marker. To improve the biochemical dia... BACKGROUND: Measurement of total serum amylase (AMY) is the most widely used biochemical test for the diagnosis of acute pancreatitis, but it is commonly considered a nonspecific marker. To improve the biochemical diagnosis of acute pancreatitis, lipase ( LIP ) and pancreatic amylase (PAMY) have been tested in recent years. The present study was designed to evaluate whether serum LIP and pancreatic PAMY tests could replace total amylase test to improve diagnostic efficiency in the evaluation of acute pancreatitis in patients with hyperamylasemia. METHODS: LIP and PAMY values were determined in serum samples from 92 patients with hyperamylasemia. Reference values for each enzyme were derived from serum samples of 147 healthy subjects. The activities of LIP and PAMY in patients with various diseases were shown directly by the boxplot graph. The diagnostic accuracy of LIP and PAMY was defined as the area under the receiver operating characteristic (ROC) curve. Their sensitivity and specificity in detecting acute pancreatitis at varying cutoff points were shown by the curve, and the best cutoff value for each enzyme was shown by the modified ROC curve. The diagnostic values of LIP, PAMY and LIP + AMY with each upper limit of reference range (ULR) were compared with the corresponding best cutoff values. RESULTS: The references values of LIP and PAMY were 12.2-47.6 U/L and 28-95 U/L, respectively. These values in patients with acute pancreatitis were higher than those patients with other diseases. The areas under the ROC curve ( AUC) of LIP and PAMY were 0. 799 and 0. 792, respectively, With the best diagnostic cutoff point of maximum (sensitivity + specificity) -100%, we obtained values of 97.9 U/L(LIP97.9 =2. 06 × ULR) for LIP and 209 U/L (PAMY209 =2.20 ×ULR) for PAMY. The best cutoff values for LIP, PAMY and LIP +AMY demonstrated the specificity, positive predictive value, and diagnostic efficiency higher than the corresponding ULRs. CONCLUSIONS: Serum LIP and PAMY are specific for the pancreas and might replace total amylase for the diagnosis of acute pancreatitis in hyperamylasemia patients. LIP97.9 is more efficient than PAMY209 in the diagnosis of acute pancreatitis. A combined test of both enzymes is not superior to single test of either enzyme in diagnostic accuracy. 展开更多
关键词 pancreatic injury lipase pancreatic amylase
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Study on low-temperature lipase of psychrophilic bacterium 2-5-10-1 isolated from deep sea of Southern Ocean 被引量:5
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作者 Lin Xuezheng1,Yang Xiuxia2,Bian Ji1,Huang Xiaohang1 1. First Institute of Oceanography,State Oceanic Administration,Qingdao 266061,China 2. Fishery College, Ocean University of China,Qingdao 266003,China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2003年第4期643-649,共7页
A strain of psychrophilic bacterium, 2-5-10-1, which produces low-temperature lipase, is isolated from the deep sea of Prydz Bay in Southern Ocean. The highest lipase secretion of this strain is observed at 5 degreesC... A strain of psychrophilic bacterium, 2-5-10-1, which produces low-temperature lipase, is isolated from the deep sea of Prydz Bay in Southern Ocean. The highest lipase secretion of this strain is observed at 5 degreesC and this temperature is also for optimal growth. Tween 80 and olive oil enhance secretion of lipase. The optimal temperature and pH for lipase activity are 35 degreesC and 7.5 degreesC respectively. At 0degreesC, the lipase still has 37% relative enzyme activity. The lipase shows high thermolability, more than 50% activity lost after incubation at 60 degreesC for 15 min. EDTA has no effect on lipase activity, indicating the lipase activity is independent of divalent cation. In contrast, the lipase activity is inhibited drastically by Cu2+ and Zn2+. 展开更多
关键词 Southern Ocean deep sea psychrophilic bacteria low-temperature lipase
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Improvement of Properties of Pseudomonas sp.Lipase in Resolution of 2-Octanol 被引量:3
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作者 WANGZhi QUANJing +4 位作者 WENGLiang ZHENGLiang-yu LIUNing DONGHuan CAOShu-gui 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2003年第4期446-449,共4页
A novel preparation method was developed to form a surfactant-lipase complex for the resolution of 2-octanol in a solvent-free system. The E value was improved from 6.64 to 120.2. The lipase modified by the anion... A novel preparation method was developed to form a surfactant-lipase complex for the resolution of 2-octanol in a solvent-free system. The E value was improved from 6.64 to 120.2. The lipase modified by the anionic surfactant possessed a low solubility in the solvent-free system, which was beneficial to the recovery and the repeated usage of the lipase. The surfactant-lipase complex maintained a high enantioselectivity after five cycles of usage. The effect of water on both the activity and the enantioselectivity of the lipase has also been investigated; the direct addition of a salt hydrate pair of Na 4P 2O 7·H 2O and Na 4P 2O 7 can dramatically activate the modified enzyme. 展开更多
关键词 lipase SURFACTANT Salt hydrate pair ESTERIFICATION ENANTIOSELECTIVITY
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Lipase immobilized on HOOC-MCF:A highly enantioselective catalyst for transesterification resolution of (R,S)-1-phenylethanol 被引量:3
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作者 Ping Xue Xiang Hui Yan Zheng Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第8期929-932,共4页
Pseudomonas cepacia lipase (PSL) immobilized on the carboxyl-functionalized meso-cellular foams (HOOC-MCF) was used for the transesterification resolution of (R,S)-l-phenylethanol in organic solvent. The results... Pseudomonas cepacia lipase (PSL) immobilized on the carboxyl-functionalized meso-cellular foams (HOOC-MCF) was used for the transesterification resolution of (R,S)-l-phenylethanol in organic solvent. The results showed that the ee value of (S)-1- phenylethanol and (R)-1-phenylethyl acetate reached 99% with 50% conversion of 1-phenylethanol using toluene as solvent. Furthermore, it was found that PSL/HOOC-MCF exhibited high enantioselectivity in organic solvent with log P ≤ 2 such as toluene and hexane. 展开更多
关键词 Immobilized lipase ENANTIOSELECTIVITY Chiral resolution 1-Phenylethanol
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