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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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Enzymatic Promiscuity: "Amano" Lipase AS-catalysed Synthesis of Naphthopyran Derivatives in Anhydrous Media 被引量:1
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作者 JIANG Ling YU Hongwei 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2014年第3期396-399,共4页
"Amano" lipase AS(lipase from Aspergillus niger), which naturally hydrolyzes triglycerides, was found promiscuously to catalyze multi-component reactions of aromatic aldehydes with malononitrile and β-naphthol to... "Amano" lipase AS(lipase from Aspergillus niger), which naturally hydrolyzes triglycerides, was found promiscuously to catalyze multi-component reactions of aromatic aldehydes with malononitrile and β-naphthol to prepare naphthopyran derivatives in anhydrous organic solvents in moderate to good yields. 展开更多
关键词 "amano lipase AS Catalytic promiscuity Multi-component reaction Naphthopyran derivative
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Bound lipase:an important form of lipase in rice bran (Oryza sativa) 被引量:1
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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 被引量:1
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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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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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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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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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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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Prokaryotic Expression of Pseudomonas Aeruginosa Lipase Gene 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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Genetic Screening of the Lipoprotein Lipase Gene for Mutations in Chinese Subjects with or without Hypertriglyceridemia 被引量:3
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作者 杨宇虹 穆云祥 +4 位作者 赵郁 刘新宇 赵莉莉 汪军梅 解用虹 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第5期381-391,共11页
Objective: To investigate the association between the mutations in lipoprotein lipase gene and hypertriglyceridemia (HTG). Methods: The lipoprotein lipase (LPL) gene was screened for mutations in 386 Chinese sub... Objective: To investigate the association between the mutations in lipoprotein lipase gene and hypertriglyceridemia (HTG). Methods: The lipoprotein lipase (LPL) gene was screened for mutations in 386 Chinese subjects with (108 cases in the HTG group) or without HTG (278 cases in the control group), by single-strand conformation polymorphism (SSCP) analysis and DNA sequencing. Results: One novel silent mutation L103L, one missense mutation P207L, three splicing mutations Int3/3' -ass/C(-6)→T, and the common S447X polymorphism has been identified in the whole coding region and exon-intron junctions of the LPL gene were examined. Heterozygous P207L found in the HTG group was the first case reported in Asia and subsequently another P207L heterozygote was found in the proband's family, all of which suggested that P207L was one of the causes of familial combined hyperlipidemia, but was not so prevalent as that in French Canadian. Int3/3'-ass/C(-6)→T was found in both groups in the present study although it was regarded as a pathogenic variant to HTG earlier on. Moreover about the beneficial polymorphism S447X, there was also some supportive evidence that the levels of triglycerides (TG) in S447X carriers were significantly lower than noncarders in the subjects without HTG. Conclusions: The association between the LPL variants and HTG is quite complicated and versatile, genotyping of LPL in a larger-scale screening should be necessary and justifiable. 展开更多
关键词 lipoprotein lipase MUTATIONS CHINESE HYPERTRIGLYCERIDEMIA
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联合检测血清Lipase、CRP和IL-6在急性胰腺炎诊断和预后判断中的价值 被引量:17
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作者 杨沛 陈伟 文爱清 《重庆医学》 CAS CSCD 2002年第11期1048-1049,共2页
目的 评价联合检测脂肪酶 (Lipase)、白细胞介素 6 (IL 6 )和C 反应蛋白 (CRP)是否能够快速诊断和有效预后急性胰腺炎。方法 检测 4 0例非胰腺炎急腹症病人 ,4 0例急性胰腺炎患者 (包括 2 5例轻型急性胰腺炎患者和 15例重症急性胰腺... 目的 评价联合检测脂肪酶 (Lipase)、白细胞介素 6 (IL 6 )和C 反应蛋白 (CRP)是否能够快速诊断和有效预后急性胰腺炎。方法 检测 4 0例非胰腺炎急腹症病人 ,4 0例急性胰腺炎患者 (包括 2 5例轻型急性胰腺炎患者和 15例重症急性胰腺炎患者 )和 4 0例健康控制组人员的血清Lipase、IL 6、CRP水平。 结果 Lipase(判定点设在 4 5 0u/L)可以正确区分 97%的急性胰腺炎患者和其它急腹症患者 ,有 2例急性胰腺炎患者Lipase低于 4 5 0u/L而未能正确区分 ,阳性预测值为 97% ,阴性预测值为 95 %。IL 6 (判定点设在 3 7μg/L) ,可以正确区分重症胰腺炎和轻度胰腺炎 ,敏感性为 10 0 % (15 / 15 ) ,特异性为 87% (2 0 / 2 3) ,阳性预测值为 88% ,阴性预测值为 10 0 % ,可以对急性胰腺炎的病情程度进行准确分级。CRP(判定点设在 6mg/L)显示预后效率低于IL 6 ,敏感性为 87% (13/ 15 ) ,特异性为 4 8% (11/ 2 3) ,阳性预值为 5 2 % ,阴性预值为 85 %。结论 联合检测Lipase、CRP和IL 6可以快速诊断急性胰腺炎和有效预后病情 ,指导临床治疗。 展开更多
关键词 胰腺炎 脂肪酶 IL-6 诊断 预后
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偏甘油酯脂肪酶Lipase G50催化酯化法制备甘油二酯 被引量:6
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作者 徐扬 王卫飞 +2 位作者 陈华勇 王永华 杨博 《中国油脂》 CAS CSCD 北大核心 2012年第2期46-50,共5页
利用偏甘油酯脂肪酶Lipase G50催化甘油和脂肪酸酯化反应合成甘油二酯。探讨了酶加量、底物摩尔比、反应温度及加水量对酯化反应的影响。结果表明最佳反应条件为:脂肪酶Lipase G50加量为350 U/g,甘油和脂肪酸的摩尔比5∶1,加水量为底物... 利用偏甘油酯脂肪酶Lipase G50催化甘油和脂肪酸酯化反应合成甘油二酯。探讨了酶加量、底物摩尔比、反应温度及加水量对酯化反应的影响。结果表明最佳反应条件为:脂肪酶Lipase G50加量为350 U/g,甘油和脂肪酸的摩尔比5∶1,加水量为底物总质量的5%,反应温度30℃,反应时间24 h。在最佳反应条件下脂肪酸的酯化率为75.02%,甘油二酯的含量达到44.74%,产物中没有甘油三酯生成。 展开更多
关键词 甘油二酯 偏甘油酯脂肪酶 酯化反应
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铜绿假单胞菌脂肪酶Lipase基因的原核表达 被引量:5
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作者 张煜星 武寒雪 +2 位作者 祝建波 刘焕 周鹏 《安徽农业科学》 CAS 北大核心 2008年第35期15384-15385,15388,共3页
[目的]对铜绿假单胞菌脂肪酶Lipase基因进行原核表达。[方法]利用PCR方法从铜绿假单胞菌基因组DNA中扩增得到脂肪酶基因,测定其核苷酸序列,利用基因重组技术构建脂肪酶基因的原核表达载体,加IPTG至终浓度为1.0 mmol/L诱导蛋白表达4 h,... [目的]对铜绿假单胞菌脂肪酶Lipase基因进行原核表达。[方法]利用PCR方法从铜绿假单胞菌基因组DNA中扩增得到脂肪酶基因,测定其核苷酸序列,利用基因重组技术构建脂肪酶基因的原核表达载体,加IPTG至终浓度为1.0 mmol/L诱导蛋白表达4 h,并进行SDS-PAGE电泳。[结果]从铜绿假单胞菌中克隆的脂肪酶基因成熟肽的序列,与NCBI上所递交的铜绿假单胞菌脂肪酶序列同源性很高,达99.36%。成功构建了脂肪酶基因的原核表达载体pET32a-Lip,进一步SDS-PAGE电泳结果显示目的基因得到高效表达。[结论]克隆的铜绿假单胞菌脂肪酶带有自身的信号肽,也可以在大肠杆菌中正常表达,可以用于进一步的研究。 展开更多
关键词 铜绿假单胞菌 脂肪酶 原核表达
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固定化脂肪酶Lipase G 50催化合成甘油二酯的研究 被引量:3
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作者 徐扬 王卫飞 +2 位作者 陈华勇 王永华 杨博 《食品工业科技》 CAS CSCD 北大核心 2012年第9期205-208,共4页
以D380、CAT600、AB-8三种大孔树脂为载体,采用物理吸附法,对偏甘油酯脂肪酶LipaseG50进行了固定化,并利用其催化脂肪酸和甘油酯化合成甘油二酯。结果表明,采用D380固定的脂肪酶酶活最高,用此固定化酶催化反应的最佳条件为:甘油和脂肪... 以D380、CAT600、AB-8三种大孔树脂为载体,采用物理吸附法,对偏甘油酯脂肪酶LipaseG50进行了固定化,并利用其催化脂肪酸和甘油酯化合成甘油二酯。结果表明,采用D380固定的脂肪酶酶活最高,用此固定化酶催化反应的最佳条件为:甘油和脂肪酸的摩尔比5∶1,固定化酶酶加量为底物总质量的7.5%,反应温度35℃,在此条件下经过96h的反应,酯化率为76.39%,甘油二酯的含量为43.89%,没有甘油三酯生成。固定化酶重复使用5个批次后酯化率可达65.76%,甘油二酯的含量达到38.45%,具有良好的重复使用稳定性。 展开更多
关键词 偏甘油酯脂肪酶 固定化 甘油二酯 酯化反应
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器壁固定化脂肪酶(Pseudomonas cepacia lipase)的非水活性与稳定性 被引量:7
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作者 李玲玲 闫倩云 +6 位作者 丛方地 周学永 刘海学 邢克智 任健 王英超 李涛 《中国生物化学与分子生物学报》 CAS CSCD 北大核心 2014年第10期1025-1030,共6页
许多脂肪酶在有机体系中表现出催化作用,可用于绿色有机合成.但其催化活性和稳定性明显低于水/油(有机相)界面上的表现.为了提高脂肪酶在有机反应体系中的活性和稳定性,依据脂肪酶的界面活化机制,以水为酶蛋白构象优化剂、羧甲基纤维素... 许多脂肪酶在有机体系中表现出催化作用,可用于绿色有机合成.但其催化活性和稳定性明显低于水/油(有机相)界面上的表现.为了提高脂肪酶在有机反应体系中的活性和稳定性,依据脂肪酶的界面活化机制,以水为酶蛋白构象优化剂、羧甲基纤维素为赋形剂,通过物理吸附的方式,将典型的假单胞菌脂肪酶(Pseudomonas cepacia lipase)固定在锥形瓶的内壁上,形成简易的生物反应器.为方便检测器壁固定化酶促反应动力学,选择特征吸收为640 nm的生化指示剂2,6-二氯靛酚为反应底物,乙酸乙烯酯为酰化试剂,丙酮为溶剂.光谱检测表明,催化反应0.5 h后,器壁固定化脂肪酶转化底物的能力是脂肪酶粉的6倍.在每次催化5 h共10次的循环催化中,器壁固定化脂肪酶的催化活性平均每次仅降低3.2%,而酶粉降低11.8%.结果表明,该器壁固定化脂肪酶的活性和稳定性相对于酶粉明显提高,这将为通过固定化有效提高脂肪酶的非水催化作用提供重要的参考. 展开更多
关键词 酶活性 稳定性 动力学 非水相 假单胞菌脂肪酶
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中国野桑蚕抗病毒蛋白基因(Lipase)的克隆与活性鉴定 被引量:8
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作者 姚慧鹏 何芳青 +3 位作者 郭爱芹 曹翠平 鲁兴萌 吴小锋 《蚕业科学》 CAS CSCD 北大核心 2008年第3期466-471,共6页
从中国野桑蚕幼虫中肠细胞克隆获得了抗家蚕核型多角体病毒BmNPV的脂肪酶基因(Lipase)cDNA(GenBank:AY945212)。该基因cDNA大小906 bp,编码301个氨基酸,蛋白质分子质量约为28.9 kD。进一步克隆了其全长基因组,结果表明该基因由2 147 bp... 从中国野桑蚕幼虫中肠细胞克隆获得了抗家蚕核型多角体病毒BmNPV的脂肪酶基因(Lipase)cDNA(GenBank:AY945212)。该基因cDNA大小906 bp,编码301个氨基酸,蛋白质分子质量约为28.9 kD。进一步克隆了其全长基因组,结果表明该基因由2 147 bp组成,包含4个外显子和3个内含子。该基因在野桑蚕体内的表达具有组织特异性,仅限于野桑蚕中肠组织表达,且在幼虫龄中表达水平较高,而在幼虫眠期和熟蚕期几乎没有表达。通过基因体外表达获得的重组蛋白Lipase,能够有效抑制BmNPV病毒对家蚕的感染,说明该蛋白具有较强的抗BmNPV的生物学活性。 展开更多
关键词 野桑蚕 脂肪酶 抗家蚕核型多角体病毒蛋白 基因克隆 活性鉴定
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“两广二号”家蚕抗病毒基因Bmlipase-1和BmSP-2克隆与原核表达 被引量:1
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作者 梁湘 陆专灵 +3 位作者 韦秉兴 冯健玲 屈达才 罗廷荣 《基因组学与应用生物学》 CAS CSCD 北大核心 2012年第4期320-326,共7页
本研究以优良杂交品种"两广二号"家蚕为试材,克隆了该杂交品种家蚕两个抗家蚕核型多角体病毒(BmNPV)基因:脂肪酶基因Bmlipase-1和丝氨酸蛋白酶基因BmSP-2,测序并分别与不同品种蚕的同源基因序列进行比较。结果显示,"两... 本研究以优良杂交品种"两广二号"家蚕为试材,克隆了该杂交品种家蚕两个抗家蚕核型多角体病毒(BmNPV)基因:脂肪酶基因Bmlipase-1和丝氨酸蛋白酶基因BmSP-2,测序并分别与不同品种蚕的同源基因序列进行比较。结果显示,"两广二号"家蚕Bmlipase-1基因ORF长度为885bp,编码294个氨基酸,BmSP-2扩增长度为855bp,编码284个氨基酸;它们的核苷酸和推导氨基酸序列同源性皆达92%以上,Bmlipase-1更保守,同源性大于99%";两广二号"家蚕的Bmlipase-1基因脂肪酶活化部位和BmSP-2基因酶催化三联体位点的氨基酸残基与不同品种蚕的完全相同。以上结果说明这两个抗病毒基因在蚕的遗传进化过程中高度保守,提示其可能在机体消化或者免疫防御方面起着重要生理作用。将这两个抗病毒基因在大肠杆菌BL21中进行融合表达,获得的融合Bmlipase-1和BmSP-2蛋白分子量分别为47kD和42kD左右。 展开更多
关键词 家蚕 脂肪酶 丝氨酸蛋白酶 克隆 表达
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家蚕脂肪酶1(Bmlipase-1)的原核表达和抗体制备及在转基因增量表达系统中的检测 被引量:2
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作者 金盛凯 蒋亮 +3 位作者 林平 孙薇 程廷才 夏庆友 《蚕业科学》 CAS CSCD 北大核心 2012年第6期1000-1004,共5页
家蚕肠液中的脂肪酶1(Bmlipase-1)对家蚕核型多角体病毒(BmNPV)具有明显抑制作用,建立的增量表达Bmlipase-1的转基因家蚕品系(LI-A)对BmNPV的抵抗力得到显著增强。为了分析LI-A品系幼虫肠液中Bmlipase-1的含量变化,通过原核表达、纯化Bm... 家蚕肠液中的脂肪酶1(Bmlipase-1)对家蚕核型多角体病毒(BmNPV)具有明显抑制作用,建立的增量表达Bmlipase-1的转基因家蚕品系(LI-A)对BmNPV的抵抗力得到显著增强。为了分析LI-A品系幼虫肠液中Bmlipase-1的含量变化,通过原核表达、纯化Bmlipase-1蛋白,并免疫家兔制备Bmlipase-1的多克隆抗体,对LI-A品系和正常家蚕品种大造4龄、5龄起蚕肠液中的Bmlipase-1含量进行Western blotting检测。结果显示Bmlipase-1在LI-A品系幼虫肠液中的含量明显高于正常家蚕品种大造,证明LI-A品系对BmNPV的抵抗力提高是因为肠液中Bmlipase-1的含量增加。 展开更多
关键词 家蚕核型多角体病毒 脂肪酶1 原核表达 多克隆抗体 转基因 抵抗力 家蚕
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枯草芽孢杆菌脂肪酶基因lipaseA突变文库构建及其生物柴油转酯研究 被引量:2
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作者 李璟 童晋 +2 位作者 罗明银 黎宸位 鲜洁 《浙江农业学报》 CSCD 北大核心 2016年第5期864-869,共6页
采用易错PCR方法对枯草芽孢杆菌脂肪酶基因lipase A进行定向进化,并首次采用对硝基苯棕榈酸酯(p NPP)法进行96孔板高通量筛选。结果表明:第一轮易错PCR没有产生随机突变,第二轮易错PCR反应在Mn^(2+)浓度为0.2 mmol·L^(-1)时,产生... 采用易错PCR方法对枯草芽孢杆菌脂肪酶基因lipase A进行定向进化,并首次采用对硝基苯棕榈酸酯(p NPP)法进行96孔板高通量筛选。结果表明:第一轮易错PCR没有产生随机突变,第二轮易错PCR反应在Mn^(2+)浓度为0.2 mmol·L^(-1)时,产生了突变菌株。对该条件下构建的文库中124株突变菌株进行p NPP高通量筛选,突变株4B_2的吸光度值A_(405)为1.395,与未突变株PET32a-lipase A(A_(405)=0.448)差异显著。测序结果表明,突变株4B_2脂肪酶基因lipase A有5个核苷酸位点发生了突变,其中3个是同义突变,2个是错义突变,分别是82位的天冬酰胺(AAU)突变为酪氨酸(UAU),143位的赖氨酸(AAG)突变为苏氨酸(ACG)。突变株4B_2发酵上清液转化生物柴油的转酯效率较对照菌PET 32a-lipase A有明显提高,前者为79.5%,后者为49.72%。本研究为枯草芽孢杆菌脂肪酶lipase A转酯活性位点的探索奠定了基础。 展开更多
关键词 枯草芽孢杆菌 脂肪酶 易错PCR 对硝基苯棕榈酸酯 转酯效率
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基于分子动力学的脂肪酶Lipase 5的热稳定性研究 被引量:4
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作者 吕建平 魏冬青 +1 位作者 王永华 徐沁 《原子与分子物理学报》 CAS CSCD 北大核心 2016年第1期128-134,共7页
天然的低温脂肪酶往往结构热稳定性比较差,制约了其长时间有效地发挥催化作用及保存.该研究以来源于白色念珠菌(Candida albicans)的低温脂肪酶Lipase 5为对象,运用相关分子动力学方法进行研究,提出了提高其热稳定性的理论策略.首先运... 天然的低温脂肪酶往往结构热稳定性比较差,制约了其长时间有效地发挥催化作用及保存.该研究以来源于白色念珠菌(Candida albicans)的低温脂肪酶Lipase 5为对象,运用相关分子动力学方法进行研究,提出了提高其热稳定性的理论策略.首先运用同源建模方法构建目标蛋白的三维结构模型;然后通过18ns分子动力学模拟,锚定目标蛋白不稳定区域中柔性氨基酸(甘氨酸)的位置,并将这些柔性氨基酸位点突变为刚性氨基酸(脯氨酸);最后利用分子动力学模拟来验证这些突变对蛋白质热稳定性的影响.结果发现,将Lipase 5三维结构中的第279位甘氨酸突变为脯氨酸后,使得蛋白质热稳定性增强.这为类似低温脂肪酶的热稳定性改造的实验设计提供了理论支持. 展开更多
关键词 低温脂肪酶 热稳定性 分子动力学模拟
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