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β-Galactosidase的应用研究
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作者 祁艳霞 张小辉 +1 位作者 王占彬 王玉琴 《中国饲料添加剂》 2007年第7期35-37,共3页
本文综述了β-galactosidase的国内外研究概况、作用机理以及来源,着重论述了β-galactosidase在畜牧生产、食品工业、制药工业等领域的应用。
关键词 Β-galactosidase 来源 应用
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Construction and Secretory Expression of β-Galactosidase Gene from Lactobacillus Bulgaricus in Lactococcus Lactis 被引量:4
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作者 ZHANG Wen WANG Chuan +4 位作者 HUANG Cheng Yu YU Qian LIU Heng Chuan ZHANG Chao Wu PEI Xiao Fang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2012年第2期203-209,共7页
Objective This study is to examine the secretion effects of β-galactosidase in Lactococcus lactis.Methods The usp45 and β-galactosidase genes were cloned and inserted into plasmid pMG36e to obtain the recombinant pl... Objective This study is to examine the secretion effects of β-galactosidase in Lactococcus lactis.Methods The usp45 and β-galactosidase genes were cloned and inserted into plasmid pMG36e to obtain the recombinant plasmid pMG36e-usp-lacZ.This recombinant plasmid was transformed into both Escherichia coli DH5α and L.lactis MG1363.The enzyme activity,gene sequencing,SDS-PAGE and hereditary stability were assessed and studied.Results The lacZ gene inserted into plasmids pMG36e-usp-lacZ was 99.37% similar to the GenBank sequence,and SDS-PAGE revealed an evident idio-strap at 116 KDa between L.lactis MG1363/pMG36eusp-lacZ in both supernatant and cell samples.β-Galactosidase activity measured 0.225 U/mL in L.lactis pMG36e-usp-lacZ transformants,and its secretion rate was 10%.The plasmid pMG36e-usp-lacZ appeared more stable in MG1363.Conclusion The authors concluded that these new recombinant bacteria well expressed and secreted β-galactosidase,indicating that the β-galactosidase expression system was successfully constructed,and this might provide a new solution for management of lactose intolerance specifically and promote the use of gene-modified organisms as part of the food-grade plasmid in general. 展开更多
关键词 Gene constructs Gene expression Secretory expression Β-galactosidase Lactococcus lactis
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Non-Fusion and Fusion Expression of β-Galactosidase from Lactobacillus bulgaricus in Lactococcus lactis 被引量:7
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作者 CHUAN WANG CHAO-WU ZHANC HENG-CHUAN LIU QIAN YU AND XIAO-FANG PEI 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2008年第5期389-397,共9页
Objective To construct four recombinant Lactococcus lactis strains exhibiting high β-galactosidase activity in fusion or non-fusion ways, and to study the influence factors for their protein expression and secretion.... Objective To construct four recombinant Lactococcus lactis strains exhibiting high β-galactosidase activity in fusion or non-fusion ways, and to study the influence factors for their protein expression and secretion. Methods The gene fragments encoding β-galactosidase from two strains of Loctobacillus bulgaricus, wch9901 isolated from yogurt and 1.1480 purchased from the Chinese Academy of Sciences, were amplified and inserted into lactococcal expression vector pMG36e. For fusion expression, the open reading frame of the β-galactosidase gene was amplified, while for non-fusion expression, the open reading frame of the β-galactosidase gene was amplified with its native Shine-Dalgarno sequence upstream. The start codon of the β-galactosidase gene partially overlapped with the stop codon of vector origin open reading frame. Then, the recombinant plasmids were transformed into Escherichia coli DH5α and Lactococcus lactis subsp, lactis MG1363 and confirmed by determining β-galactosidase activities. Results The non-fusion expression plasmids showed a significantly higher β-galactosidase activity in transformed strains than the fusion expression plasmids. The highest enzyme activity was observed in Lactococcus lactis transformed with the non-fusion expression plasmids which were inserted into the β-galactosidase gene from Lactobacillus bulgaricus wch9901. The β-galactosidase activity was 2.75 times as high as that of the native counterpart. In addition, β-galactosidase expressed by recombinant plasmids in Lactococcus lactis could be secreted into the culture medium. The highest secretion rate (27.1%) was observed when the culture medium contained 20 g/L of lactose. Conclusion Different properties of the native bacteria may have some effects on the protein expression of recombinant plasmids. Non-fusion expression shows a higher enzyme activity in host bacteria. There may be a host-related weak secretion signal peptide gene within the structure gene of Lb. bulgaricus β-galactosidase, and its translation product may introduce the enzyme secretion out of cells in special hosts. 展开更多
关键词 Β-galactosidase Lactococcus lactis Lactose intolerance Protein expression Protein secretion.
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Construction of a Food-Grade Expression Vector Based on pMG36e by Using an α-Galactosidase Gene as a Selectable Marker 被引量:2
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作者 GU Xin-xi TAN Jian-xin +3 位作者 TIAN Hong-tao ZHANG Yu-lan LUO Yun-bo GUO Xing-hua 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第8期1802-1808,共7页
Construction of a food-grade expression vector for application to lactic acid bacteria(LAB) is of importance for dairy fermentation system. An α-galactosidase(aga) gene encoding an enzyme degrading melibiose was ... Construction of a food-grade expression vector for application to lactic acid bacteria(LAB) is of importance for dairy fermentation system. An α-galactosidase(aga) gene encoding an enzyme degrading melibiose was amplified by PCR from the plasmid p RAF800 of Lactococcus lactis NZ9000. The aga gene was introduced into pMG36 e to substitute the p rimary antibiotic selectable marker of pMG36 e, resulting in construction of a new food-grade expression vector pMG36-aga. To testify the expression efficiency of exogenous gene in pMG36-aga, a 1.5 kb long α-amylase(amy) gene from Ba cillus li cheniformis was cloned by PCR and introduced into the plasmid pMG36-aga. The resultant plasimd pMG36-aga-amy was transformed into L. lactis ML23 by electroporation. The positive clones were selected with the medium containing melibiose as the sole carbon source. Th e selection efficiency of aga was 8.71×103 CFU with a standard deviation of 9.1×102 CFU ?g-1 DNA of pMG36-aga. Furthermore, the SDS-PAGE analysis showed that the pMG36-aga-amy expressed a 56.4 kDa protein which was the same as the putati ve molecular weight of α-amylase. The starch plate assay also indicated that L. lactis ML23 displayed high activity of α-amylase by expressing of amy gene of pMG36-aga-amy. 展开更多
关键词 food-grade expression vector Lactococcus lactis α-galactosidase gene amylase gene pMG36e
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Identification of an intestine-specific promoter and inducible expression of bacterial α-galactosidase in mammalian cells by a lac operon system 被引量:1
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作者 Zhai Ya-Feng Shu Gang +6 位作者 Zhu Xiao-Tong Zhang Zhi-Qi Lin Xia-Jing Wang Song-Bo Wang Li-Na Zhang Yong-Liang Jiang Qing-Yan 《Journal of Animal Science and Biotechnology》 SCIE CAS 2013年第1期65-74,共10页
Background: o-galactosidase has been widely used in animal husbandry to reduce anti-nutritional factors (such as o-galactoside) in feed. Intestine-specific and substrate inducible expression of a-galactosidase woul... Background: o-galactosidase has been widely used in animal husbandry to reduce anti-nutritional factors (such as o-galactoside) in feed. Intestine-specific and substrate inducible expression of a-galactosidase would be highly beneficial for transgenic animal production. Methods: To achieve the intestine-specific and substrate inducible expression of o-galactosidase, we first identified intestine-specific promoters by comparing the transcriptional activity and tissue specificity of four intestine-specific promoters from human intestinal fatty acid binding protein, rat intestinal fatty acid binding protein, human mucin-2 and human lysozyme. We made two chimeric constructs combining the promoter and enhancer of human mucin-2, rat intestinal trefoil factor and human sucrase-isomaltase. Then a modified lac operon system was constructed to investigate the induction of o-galactosidase expression and enzyme activity by isopropyl p-D-]-thiogalactopyranoside (IPTG) and an a-galactosidase substrate, a-lactose. We declared that the research carried out on human (Zhai Yafeng) was in compliance with the Helsinki Declaration and experimental research on animals also followed internationally recognized guidelines. Results: The activity of the human mucin-2 promoter was about 2 to 3 times higher than that of other intestine-specific promoters. In the/ac operon system, the repressor significantly decreased (P 〈 0.05) luciferase activity by approximately 6.5-fold and reduced the percentage of cells expressing green fluorescent protein (GFP) by approximately 2-fold. In addition, the expression level of o-galactosidase mRNA was decreased by 6-fold and a-galactosidase activity was reduced by 8-fold. in line with our expectations, IPTG and a-lactose supplementation reversed (P 〈 O.O5) the inhibition and produced a 5-fold increase of luciferase activity, an 11-fold enhancement in the percentage of cells with GFP expression and an increase in o-galactosidase mfiNA abundance (by about 5-fold) and o-galactosidase activity (by about 7-fold). Conclusions: We have successfully constructed a high specificity inducible lac operon system in an intestine-derived cell line, which could be of great value for gene therapy applications and transgenic animal production. 展开更多
关键词 a-galactosidase Inducible expression Intestine-specific promoters Lac operon
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Development of Non-Labeled QCM Biosensor for the Detection of <i>β</i>-Galactosidase: A Comparative Study of Gold and Polystyrene Nanoparticles 被引量:1
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作者 Krishna Pal Singh Manav Kumar Choudhary +1 位作者 Iva Chianella Prashant Singh 《Advances in Nanoparticles》 2013年第2期182-190,共9页
The performance of gold and polystyrene nanoparticles was investigated using quartz crystal microbalance (QCM) as sensor platform;β-Galactosidase antibody with corresponding antigen was utilized for the immunoreactio... The performance of gold and polystyrene nanoparticles was investigated using quartz crystal microbalance (QCM) as sensor platform;β-Galactosidase antibody with corresponding antigen was utilized for the immunoreaction. The development of the immunosensor included: 1) formation of self assembled monolayers on quartz crystals;2a) immobilization of p-aminothiophenol functionalized gold nanoparticles on carboxyl-terminated self assembled monolayer, or 2b) immobilization of polystyrene nanoparticles on crystals modified with p-aminothiophenol self assembled monolayer;3) attachment of monoclonal anti β-Gal on nanoparticles;and 4) detection of target analyte. The nanoparticles used were synthesized in house and characterized by transmission electron microscopy and infrared spectroscopy. The results revealed that antibodies were strongly attached to functionalized gold nanoparticles;the weaker immobilization of antibodies to polystyrene nanoparticles provoked their detachment during antigen detection. When cross reactivity of polystyrene nanoparticles was checked using a different antigen (Brucella), displacement of antibody was not recorded, demonstrating specificity of the reaction. To the best of our knowledge this is the first direct comparison between behaviors of biosensors developed with two commonly used nanoparticles. The results showed that both nanoparticles produced biosensors capable to detect β-Gal. Nevertheless biosensors developed using polystyrene nanoparticles are simpler, cheaper and more eco-friendly than those developed using gold nanoparticles. 展开更多
关键词 QCM BIOSENSOR β-galactosidase GOLD NANOPARTICLE POLYSTYRENE NANOPARTICLE
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EXPRESSION OF HUMAN α-GALACTOSIDASE AND α1,2-FUCOSYL-TRANSFERASE GENES MODIFIES THE CELL SURFACE GALα1,3GAL ANTIGEN AND CONFERS RESISTANCETO HUMAN SERUM-MEDIATED CYTOLYSIS
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作者 贾延军 任会明 +5 位作者 高新 季守平 杨军 刘泽鹏 李素波 章扬培 《Chinese Medical Sciences Journal》 CAS CSCD 2004年第1期31-37,共7页
Objective To explore the strategies which reduce the amount of xenoantigen Galα1, 3 Gal. Methods Human α-galactosidase gene and α1,2-fucosyltransferase gene were transferred into cul-tured porcine vascular endothel... Objective To explore the strategies which reduce the amount of xenoantigen Galα1, 3 Gal. Methods Human α-galactosidase gene and α1,2-fucosyltransferase gene were transferred into cul-tured porcine vascular endothelial cells PEDSV.15 and human α-galactosidase transgenic mice were produced. The Galα1,3Gal on the cell surface and susceptibility of cells to human antibody-mediated lysis were analyzed. Results Human α-galactosidase gene alone reduced 78% of Galα1,3Gal on PEDSV.15 cell surface while human α-galactosidase combined with α1,2-fucosyltransferase genes removed Galα1,3Gal completely. Decrease of Galα1,3Gal could reduce susceptibility of cells to human antibody-mediated lysis, especially during co-expression of α-galactosidase gene and α1,2-fucosyltransferase gene. RT-PCR indicated positive human α-galactosidase gene expression in all organs of positive human α-galacto-sidase transgenic F1 mice including heart, liver, kidney, lung, and spleen, the amount of Galα1,3Gal antigens on which was reduced largely. 58% of spleen cells from F1 mice were destroyed by comp-lement-mediated lysis compared with 24% of those from normal mice. Conclusions Human α-galactosidase gene and α1,2-fucosyltransferase gene effectively reduce the expression of Galα1,3Gal antigens on endothelial cell surface and confers resistance to human serum-mediated cytolysis. The expression of human α-galactosidase in mice can also eliminate the Galα1,3Gal antigens in most tissues and decrease the susceptibility of spleen cells to human serum-mediated cytolysis. 展开更多
关键词 galactosidase gene hyperacute rejection Galα1 3Gal antigen
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Construction and Expression of β-galactosidase Genetically Engineered Lactococcus lactis 被引量:1
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作者 吕晓英 张朝武 +3 位作者 裴晓方 刘祥 余倩 刘衡川 《Journal of Microbiology and Immunology》 2004年第4期243-249,共7页
Our objective is to solve the lactose malabsorption and intolerance of human beings by combining micro-ecology path with genetic engineering technique. Plasmid pMG36e was used to clone and express a β-galactosidase g... Our objective is to solve the lactose malabsorption and intolerance of human beings by combining micro-ecology path with genetic engineering technique. Plasmid pMG36e was used to clone and express a β-galactosidase gene from L. delbrueckü bulgaricus strain 1.1480 in the Lactococcus lactis subsp. cremoris MG1363 and Lactococcus lactis subsp. lactis IL1403. The recombinant plasmid was preserved and proliferated in Escherichia coli ( E. coli) JM109, and transformed into MG1363 and IL1403 by electroporation. The protein expression was studied. ( 1 ) The bifidobacterium culture medium ( BBL) was suitable for the growth of the strain 1.1480. (2) With 13 amino acids at the N-terminus from the vector, β-gal- actosidase fusion protein (which retained the enzyme activity) could be successfully expressed in E. coli JM109, MG1363 and IL1403, but the expression quantity was larger in the former than in the latter two. (3) The SD sequence designed could be successfully recognized by both the E. coli and the Lactococcus lactis, but the expression level of the non-fusion β-galac- tosidase protein was lower than that of the fusion protein in the same host. The β-galactosidase genetically engineered E. coli JM109 is a useful tool to produce this enzyme in vitro . The signal peptide of the usp45 protein from the Lactococcus lac- tis can be added before the promoter sequence to promote β-galactosidase secretion from Lactococcus lactis . The potential ap- plication of the β-galactosidase genetically engineered MG1363 and IL1403 to cure the lactose malabsorption and lactose in- tolerance in both health food and medicine is promising. 展开更多
关键词 galactosidase Lactic acid bacteria L. delbrueckii bulgaricus ljactococcus lactis Plasmid Genetic engi- neering
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Kinetic Studies on <i>β</i>-Galactosidase Isolated from Apricots (<i>Prunus armeniaca kaisa</i>)
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作者 Sadaf Gulzar Shajrul Amin 《American Journal of Plant Sciences》 2012年第5期636-645,共10页
β-galactosidase was extracted from apricots (Prunus armeniaca kaisa) and characterized biochemically. Three isoenzymes (β-gal I, β-gal II and β-gal III) were obtained by salt fractionation and ionexchange and Seph... β-galactosidase was extracted from apricots (Prunus armeniaca kaisa) and characterized biochemically. Three isoenzymes (β-gal I, β-gal II and β-gal III) were obtained by salt fractionation and ionexchange and Sephadex G-100 column chromatography. β-galactosidase II showed a high ability to hy-drolyze the substrate p-nitrophenyl β-D-galactopyranoside than that of β-galactosidase I and III. The individual peaks showed charge homogeneity as revealed by single band on polyacrylamide gel. The molecular weight of β-gal I, β-gal II and β-gal III as determined by gel filtration was found to be 44.15, 34.70 and 23.71 KDa respectively. The optimum pH for the activity different isozymes was found between 4 and 6. The isoenzymes were determined to be thermally stable upto 40?C. The Km value for β-gal I was 1.85 mM which was higher than that of β-gal II (Km = 1.7), and β-gal III (Km = 1.19). The Vmax value for β-gal I, β-gal II and β-gal III was found to be 0.52, 0.70 and 0.38 μmole/min respectively. 展开更多
关键词 Β-galactosidase APRICOTS CHROMATOGRAPHY Enzyme Kinetics
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适冷β-半乳糖苷酶及其在食品工业中的应用
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作者 周玲 龚金炎 +3 位作者 何光华 肖功年 许韩山 李玲 《食品与发酵工业》 CAS CSCD 北大核心 2024年第3期314-320,共7页
β-半乳糖苷酶,又称乳糖酶,广泛存在于细菌、真菌、酵母菌等微生物中,主要功能是乳糖水解和合成低聚半乳糖。利用β-半乳糖苷酶生产低乳糖牛奶等乳制品成为解决乳糖不耐受问题最有效的途径,然而常用的商业化β-半乳糖苷酶的最适反应温... β-半乳糖苷酶,又称乳糖酶,广泛存在于细菌、真菌、酵母菌等微生物中,主要功能是乳糖水解和合成低聚半乳糖。利用β-半乳糖苷酶生产低乳糖牛奶等乳制品成为解决乳糖不耐受问题最有效的途径,然而常用的商业化β-半乳糖苷酶的最适反应温度大多较高,对pH的要求比较严格,存在生产成本较高、消耗能量高等问题。适冷β-半乳糖苷酶在低温下也具有较高的酶活性,广泛应用于食品行业中,尤其在乳品工业。在低温下水解乳糖,生产低乳糖或无乳糖乳制品,供乳糖不耐受者食用,可降低成本、节约能源,具有重要意义。该文综述了β-半乳糖苷酶的微生物来源、特性、催化特性的研究现状,对适冷β-半乳糖苷酶的来源、特性、耐冷机制及工业化应用进行了系统阐述,并对其前景进行了展望。 展开更多
关键词 Β-半乳糖苷酶 适冷β-半乳糖苷酶 耐冷机制
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园艺作物果实β-半乳糖苷酶研究进展
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作者 俞沁佩 孙鹂 +3 位作者 张淑文 俞浙萍 郑锡良 戚行江 《浙江农业学报》 CSCD 北大核心 2024年第9期2184-2192,共9页
β-半乳糖苷酶属于糖苷水解酶GH35家族,参与了植物不同生长阶段细胞壁的合成与修饰,尤其对肉质水果发育和成熟过程中多糖的裂解具有重要作用。文章概述了β-半乳糖苷酶的蛋白功能、不同亚型、亚细胞定位和活性规律,重点阐述了该基因家... β-半乳糖苷酶属于糖苷水解酶GH35家族,参与了植物不同生长阶段细胞壁的合成与修饰,尤其对肉质水果发育和成熟过程中多糖的裂解具有重要作用。文章概述了β-半乳糖苷酶的蛋白功能、不同亚型、亚细胞定位和活性规律,重点阐述了该基因家族在园艺作物果实质地变化中的作用及相关研究进展。 展开更多
关键词 Β-半乳糖苷酶 园艺作物 果实软化 基因功能
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丁苯酞拮抗依托泊苷诱导的血管内皮细胞衰老
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作者 赵凌蔚 叶周恒 +2 位作者 程龙 刘昕 韩磊 《中华老年心脑血管病杂志》 CAS 北大核心 2024年第3期327-330,共4页
目的 探讨丁苯酞(3-n-butylphthalide, NBP)对依托泊苷诱导人脐静脉内皮细胞(human umbilical vein endothelial cells, HUVEC)衰老的影响。方法 将HUVEC分为空白对照组(内皮细胞培养液)、依托泊苷组(500 nmol/L依托泊苷+二甲基亚砜)、... 目的 探讨丁苯酞(3-n-butylphthalide, NBP)对依托泊苷诱导人脐静脉内皮细胞(human umbilical vein endothelial cells, HUVEC)衰老的影响。方法 将HUVEC分为空白对照组(内皮细胞培养液)、依托泊苷组(500 nmol/L依托泊苷+二甲基亚砜)、依托泊苷+NBP低浓度组(500 nmol/L依托泊苷+5μmol/L NBP)、依托泊苷+NBP中浓度组(500 nmol/L依托泊苷+10μmol/L NBP)、依托泊苷+NBP高浓度组(500 nmol/L依托泊苷+20μmol/L NBP)组。通过衰老相关β半乳糖苷酶(SA-β-gal)染色检测衰老细胞比例变化;实时荧光定量聚合酶链反应检测衰老相关分泌表型,如白细胞介素(IL)-8、IL-1β、CXC趋化因子配体1(CXCL1)mRNA水平变化;蛋白质免疫印迹检测衰老相关蛋白P21表达水平变化;免疫荧光染色检测增殖相关蛋白Ki67阳性细胞比例变化。结果 与空白对照组比较,依托泊苷组P21表达、SA-β-gal染色阳性细胞比例、IL-8、IL-1β、CXCL1的mRNA水平均显著升高[1.00±0.00 vs 0.59±0.09、(29.58±4.51)%vs(11.27±1.18)%、2.49±0.11 vs 1.00±0.03、6.32±0.15 vs 1.00±0.03、2.40±0.24 vs 1.00±0.04,P<0.05],Ki67阳性细胞比例显著降低[(5.95±1.55)%vs(27.38±7.00)%,P<0.05];与依托泊苷组比较,依托泊苷+NBP低浓度组的SA-β-gal染色阳性细胞比例、P21蛋白表达水平、IL-1β的mRNA水平均降低(P<0.05),Ki67阳性细胞比例增加(P<0.05)。结论 NBP对依托泊苷诱导的血管内皮细胞衰老具有拮抗作用。 展开更多
关键词 依托泊甙 人脐静脉内皮细胞 β半乳糖苷酶类 衰老相关分泌表型 丁苯酞
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益生菌和益生元缓解乳糖不耐受的研究进展
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作者 刘晴 王思琪 +1 位作者 张晏维 杜鹏 《中国乳品工业》 CAS 北大核心 2024年第4期50-55,共6页
文章阐述了乳糖不耐受及其治疗方法等相关问题,具体介绍了益生菌和益生元在缓解乳糖不耐受症状中的主要作用机制和临床治疗效果,并基于益生菌和益生元的作用优势,为研发缓解乳糖不耐受的健康替代品提出合理建议。旨在探讨益生菌和益生... 文章阐述了乳糖不耐受及其治疗方法等相关问题,具体介绍了益生菌和益生元在缓解乳糖不耐受症状中的主要作用机制和临床治疗效果,并基于益生菌和益生元的作用优势,为研发缓解乳糖不耐受的健康替代品提出合理建议。旨在探讨益生菌和益生元在缓解乳糖不耐受症状中的作用及应用,为研发相关产品提供理论依据和方向指引。 展开更多
关键词 乳糖不耐受 益生菌 益生元 Β-半乳糖苷酶 肠道菌群
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植物乳杆菌1-9代谢水苏糖机制研究
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作者 刘天仪 张文静 +2 位作者 廖强 毛咏荷 刘军 《食品科学技术学报》 EI CAS CSCD 北大核心 2024年第2期84-92,共9页
从发酵羊乳中筛选分离得到1株乳酸菌,经分子生物学鉴定为植物乳杆菌1-9,且该菌株对水苏糖具有优异的代谢效果。为研究植物乳杆菌1-9代谢水苏糖机制,以水苏糖为唯一碳源绘制生长曲线并通过高效液相色谱法分析代谢产物短链脂肪酸含量变化... 从发酵羊乳中筛选分离得到1株乳酸菌,经分子生物学鉴定为植物乳杆菌1-9,且该菌株对水苏糖具有优异的代谢效果。为研究植物乳杆菌1-9代谢水苏糖机制,以水苏糖为唯一碳源绘制生长曲线并通过高效液相色谱法分析代谢产物短链脂肪酸含量变化,采用薄层层析法探究植物乳杆菌1-9代谢水苏糖历程,在监控水苏糖关键代谢酶基因表达的基础上分析发酵液中相关酶活变化。结果表明:植物乳杆菌1-9代谢水苏糖产生的主要短链脂肪酸为乙酸和戊酸,发酵液中最高质量浓度分别为28.64 mg/mL和2.74 mg/mL;短链脂肪酸的积累导致发酵液pH值显著降低至4.00左右。结合水苏糖代谢历程、基因表达及酶活变化,推断植物乳杆菌1-9基因组中5-359可编码α-半乳糖苷酶,其作用于水苏糖末端α-半乳糖苷键,生成半乳糖、少量乳糖和蔗糖并被植物乳杆菌1-9代谢。研究结果旨在为基于植物乳杆菌与水苏糖的合生元的合理设计及相关产品开发提供理论参考。 展开更多
关键词 植物乳杆菌1-9 水苏糖 代谢机制 Α-半乳糖苷酶 基因组分析
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普通烟草β-半乳糖苷酶基因(NtBGAL)的生信分析及其在不同组织及原核诱导的表达
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作者 曹领改 刘杰 +2 位作者 张洁 张盼 余世洲 《西南农业学报》 CSCD 北大核心 2024年第6期1220-1227,共8页
【目的】探明普通烟草β-半乳糖苷酶基因NtBGAL的表达模式与蛋白特征,为后期创制烟草多用途利用的底盘材料提供依据。【方法】通过比对普通烟草K326基因序列与本氏烟草NbBGAL1基因的同源性,以K326的cDNA为模板经PCR技术克隆获得NtBGAL基... 【目的】探明普通烟草β-半乳糖苷酶基因NtBGAL的表达模式与蛋白特征,为后期创制烟草多用途利用的底盘材料提供依据。【方法】通过比对普通烟草K326基因序列与本氏烟草NbBGAL1基因的同源性,以K326的cDNA为模板经PCR技术克隆获得NtBGAL基因,随后利用生信工具软件分析其基因结构及蛋白理化性质,并采用qRT-PCR检测该基因在烟草不同组织部位(根、茎、叶和花)的表达模式,最后开展原核诱导表达、蛋白纯化及蛋白表征研究。【结果】克隆获得烟草NtBGAL基因,其与本氏烟草NbBGAL1基因同源性最高,二者具有相同的结构域(Motif);该基因定位于9号染色体上,含有18个内含子,mRNA长度为6649 bp,CDS长度为2541 bp,编码846个氨基酸,翻译的β-半乳糖苷酶属于GH35家族,NtBGAL蛋白的分子量为92.44 kDa,理论等电点(pI)为6.8,GRAVY为-0.222,定位于细胞壁。该基因在普通烟草不同组织部位的表达量为花>叶>茎>根,差异显著。在37℃下进行原核诱导,NtBGAL蛋白有明显表达;采用包涵体纯化方法获得较高纯度的NtBGAL蛋白。NtBGAL蛋白酶促反应最适温度为30~40℃,最适pH为4.0~6.5,Mn^(2+)浓度为0.05~0.15 mmol/L时对NtBGAL酶活性有增强作用。【结论】研究明确NtBGAL基因的组织表达模式及蛋白表征,为进一步通过改造NtBGAL基因,利用普通烟草生产人源化糖蛋白奠定基础。 展开更多
关键词 烟草 NtBGAL基因 Β-半乳糖苷酶 生信分析 原核诱导 蛋白表征
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miR-212-3p靶向MAPK3调控骨髓间充质干细胞的衰老
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作者 钟丽颖 李顺东 王聪 《中国组织工程研究》 CAS 北大核心 2025年第13期2690-2697,共8页
背景:骨质疏松症患者的骨髓间充质干细胞表现出明显衰老状态,并且细胞活性及成骨分化水平显著降低。miR-212-3p能够抑制人骨髓间充质干细胞的成骨分化,但其对骨髓间充质干细胞衰老调控的作用及机制尚不明确。目的:研究miR-212-3p通过靶... 背景:骨质疏松症患者的骨髓间充质干细胞表现出明显衰老状态,并且细胞活性及成骨分化水平显著降低。miR-212-3p能够抑制人骨髓间充质干细胞的成骨分化,但其对骨髓间充质干细胞衰老调控的作用及机制尚不明确。目的:研究miR-212-3p通过靶向丝裂原活化蛋白激酶3(mitogen-activated protein kinase 3,MAPK3)对骨髓间充质干细胞衰老的影响及其机制。方法:体外分离培养大鼠骨髓间充质干细胞,收集第3代进行以下实验:①分2组培养:对照组加入完全培养基,造模组加入含H_(2)O_(2)的完全培养基培养,培养72 h后,检测细胞中β-半乳糖苷酶活性、miR-212-3p和MAPK3 mRNA表达,以及MAPK3、p16和p21蛋白表达。②分3组培养:对照组、抑制物对照组、miR-212-3p抑制物组,转染24 h后,检测细胞中miR-212-3p、MAPK3 mRNA表达及MAPK3蛋白表达。③采用双荧光素酶报告基因联合qRT-PCR和Western blot验证miR-212-3p与MAPK3靶向调控作用。④分组培养:分为对照抑制物组、miR-212-3p抑制物组、miR-212-3p抑制物+干扰对照组、miR-212-3p抑制物+MAPK3干扰组,转染24 h后,检测细胞中MAPK蛋白与mRNA表达。分为对照组、H_(2)O_(2)组、H_(2)O_(2)+对照抑制物组、H_(2)O_(2)+miR-212-3p抑制物组、H_(2)O_(2)+miR-212-3p抑制物+干扰对照组、H_(2)O_(2)+miR-212-3p抑制物+MAPK3干扰组,细胞转染24 h后再加入H_(2)O_(2)培养72 h,检测细胞中衰老相关β-半乳糖苷酶活性、p16和p21蛋白表达。结果与结论:①与对照组比较,造模组β-半乳糖苷酶活性、miR-212-3p mRNA表达及p16、p21蛋白表达升高(P<0.05),MAPK3 mRNA和蛋白表达降低(P<0.05)。②与对照组比较,miR-212-3p抑制物组细胞中miR-212-3p mRNA表达降低(P<0.05),MAPK3 mRNA与蛋白表达升高(P<0.05)。③双荧光素酶报告基因实验证实,MAPK3是miR-212-3p下游靶基因。④与对照抑制物组比较,miR-212-3p抑制物组细胞中MAPK3 mRNA和蛋白表达升高(P<0.05);与miR-212-3p抑制物组比较,miR-212-3p抑制物+MAPK3干扰组细胞中MAPK3 mRNA和蛋白表达降低(P<0.05)。与H_(2)O_(2)+对照抑制物组比较,H_(2)O_(2)+miR-212-3p抑制物组β-半乳糖苷酶活性降低(P<0.05);与H_(2)O_(2)+miR-212-3p抑制物组比较,H_(2)O_(2)+miR-212-3p抑制物+MAPK3干扰组β-半乳糖苷酶活性升高(P<0.05)。与H_(2)O_(2)+对照抑制物组比较,H_(2)O_(2)+miR-212-3p抑制物组细胞中p16和p21蛋白表达降低(P<0.05);与H_(2)O_(2)+miR-212-3p抑制物组比较,H_(2)O_(2)+miR-212-3p抑制物+MAPK3干扰组细胞中p16和p21蛋白表达升高(P<0.05)。⑤结果表明,下调miR-212-3p可抑制大鼠骨髓间充质干细胞衰老,其作用机制可能是通过靶向上调MAPK3表达实现的。 展开更多
关键词 骨髓间充质干细胞 细胞衰老 miR-212-3p 丝裂原活化蛋白激酶3 Β-半乳糖苷酶
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基于水-甲醇体系的ONPG法测定调制乳粉中乳糖酶活力研究 被引量:1
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作者 马跃龙 张益萍 褚佳玥 《中国乳品工业》 CAS 北大核心 2023年第9期47-51,共5页
建立了基于水-甲醇体系的ONPG法测定调制乳粉中乳糖酶活力的测定方法。调制乳粉中的乳糖酶经水溶解提取,在特定温度、pH条件下将ONPG水解生成ONP和半乳糖,以碳酸钠作为反应终止剂,使ONP显色,加入甲醇去除杂质,分光光度法定量,计算酶活... 建立了基于水-甲醇体系的ONPG法测定调制乳粉中乳糖酶活力的测定方法。调制乳粉中的乳糖酶经水溶解提取,在特定温度、pH条件下将ONPG水解生成ONP和半乳糖,以碳酸钠作为反应终止剂,使ONP显色,加入甲醇去除杂质,分光光度法定量,计算酶活力。首次提出的基于水-甲醇体系的ONPG分光光度法,较好地去除杂质,并提高了响应,在0.005~0.15 mmol/L范围内线性相关系数0.9997,加标回收率95.0%~98.8%,相对标准偏差0.78%~0.98%,定量限1.0 U/g。该方法线性良好,结果可靠,可以作为常规实验室测定调制乳粉中乳糖酶活力的经济、可靠的测定方法。 展开更多
关键词 乳糖酶 ONPG 酶活力 调制乳粉
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日粮添加α-半乳糖苷酶对断奶苏姜仔猪生长性能、养分消化率及血清免疫指标的影响
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作者 韩大勇 周明夏 +2 位作者 朱爱文 倪黎纲 张伟 《中国饲料》 北大核心 2023年第24期50-53,共4页
本试验将不同水平的α-半乳糖苷酶添加到断奶苏姜仔猪日粮中,研究对其生长性能、血清免疫指标和养分消化率的影响。试验将108只断奶苏姜仔猪平均分为4组,每组3个重复,每个重复9只仔猪,分别为对照组(喂养普通日粮)、试验Ι组(日粮+50U/kg... 本试验将不同水平的α-半乳糖苷酶添加到断奶苏姜仔猪日粮中,研究对其生长性能、血清免疫指标和养分消化率的影响。试验将108只断奶苏姜仔猪平均分为4组,每组3个重复,每个重复9只仔猪,分别为对照组(喂养普通日粮)、试验Ι组(日粮+50U/kgα-半乳糖苷酶)、试验Ⅱ组(日粮+100U/kgα-半乳糖苷酶)、试验Ⅲ组(日粮+200U/kgα-半乳糖苷酶),试验期为40d。结果发现:与对照组相比,在日粮中添加不同水平的α-半乳糖苷酶对断奶苏姜仔猪的末重、平均日增重及料重比均有显著影响(P<0.05),其中添加100U/kgα-半乳糖苷酶对提高断奶苏姜仔猪的生长性能效果最显著(P<0.05),断奶苏姜仔猪平均日增重比对照组提高了9.07%,料重比较对照组降低了8.82%;其次,在日粮中添加不同水平的α-半乳糖苷酶对断奶苏姜仔猪血清中的IgA、IgG、IgM等免疫指标均有显著影响(P<0.05),其中添加100U/kgα-半乳糖苷酶的试验组免疫指标与对照组相比差异最显著(P<0.05),IgA、IgG、IgM分别提高16.5%、21.6%和52.9%。最后,在日粮中添加不同水平的α-半乳糖苷酶,对断奶苏姜仔猪的养分消化率也有显著影响(P<0.05),其中添加100U/kgα-半乳糖苷酶的试验组养分消化率与对照组相比差异最显著(P<0.05),粗纤维消化率和粗蛋白质消化率分别比对照组提高8.29%和8.02%。结果表明,在日粮中添加100U/kg的α-半乳糖苷酶,对断奶苏姜仔猪的生长促进效果最明显,可使断奶苏姜仔猪的饲料效率最佳。 展开更多
关键词 Α-半乳糖苷酶 仔猪 生长性能 免疫球蛋白 消化率
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β-半乳糖苷酶荧光探针的研究进展
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作者 李敏艳 闫新豪 《化学与生物工程》 CAS 2023年第4期1-6,共6页
β-半乳糖苷酶属于糖苷水解酶,在食品工业、基因工程、酶工程、蛋白质工程、生物医学等领域发挥着重要作用。β-半乳糖苷酶活性及含量的异常与癌症的发生发展密切相关,因此该酶检测对早期癌症诊断有着重要意义。传统酶活性检测方法具有... β-半乳糖苷酶属于糖苷水解酶,在食品工业、基因工程、酶工程、蛋白质工程、生物医学等领域发挥着重要作用。β-半乳糖苷酶活性及含量的异常与癌症的发生发展密切相关,因此该酶检测对早期癌症诊断有着重要意义。传统酶活性检测方法具有一定的局限性,无法实现对β-半乳糖苷酶的原位无损检测。荧光探针因灵敏度高、选择性好、可用显微镜直接观察、分辨率高、响应时间短、操作方便、成本低等优点深受研究者青睐。在简述荧光探针设计原理的基础上,对近年来β-半乳糖苷酶荧光探针的设计合成研究进展进行了综述,阐述了β-半乳糖苷酶荧光探针在生物成像、早期癌症诊断等应用进展,为β-半乳糖苷酶高效检测技术的研究提供了帮助。 展开更多
关键词 Β-半乳糖苷酶 荧光探针 生物成像
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耐热性α-半乳糖苷酶突变体的筛选及酶学性质研究
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作者 马焕 张秀江 +5 位作者 胡虹 冯菲 解复红 向凌云 武艳芳 刁文涛 《饲料研究》 CAS 北大核心 2023年第9期80-84,共5页
研究旨在改造株链球菌来源的α-半乳糖苷酶基因Gal_(2)7A,获得耐热性高的突变体。在常规PCR体系中加入不同水平的MnCl_(2),将基因克隆至载体pGAPZαA并成功构建表达酶产物的重组质粒pGAPZαA-Gal_(2)7A。将线性化的重组质粒电转至毕赤酵... 研究旨在改造株链球菌来源的α-半乳糖苷酶基因Gal_(2)7A,获得耐热性高的突变体。在常规PCR体系中加入不同水平的MnCl_(2),将基因克隆至载体pGAPZαA并成功构建表达酶产物的重组质粒pGAPZαA-Gal_(2)7A。将线性化的重组质粒电转至毕赤酵母GS115,在含有100 g/L博来霉素的YPDS平板上筛选耐热性提高的突变体,通过pNPG的方法测定重组酶的酶学性质为最适温度65℃,最适pH值6.5,Ag^(2+)、Hg^(2+)对重组酶的酶学活性具有明显的抑制作用,Cu^(2+)对重组酶的酶活性具有促进作用。研究表明,试验成功构建耐热α-半乳糖苷酶高效表达菌株29和54,在55℃保温10 min与同等条件下的野生型进行对比,加热前后的保留酶活比的增幅大于45%。 展开更多
关键词 Α-半乳糖苷酶 耐温性 重组质粒pGAPZαA-Gal27A 保留酶活比 酶学性质
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