This study was aimed to analyze the effect of procyanidin B2(PC)and tannin acid(TA)on the activities of cholesterol esterase(CEase)and the inhibitory mechanisms of enzymatic activity.The interaction mechanisms were in...This study was aimed to analyze the effect of procyanidin B2(PC)and tannin acid(TA)on the activities of cholesterol esterase(CEase)and the inhibitory mechanisms of enzymatic activity.The interaction mechanisms were investigated by enzymatic kinetics,multi-spectroscopy methods,thermodynamics analysis,molecular docking,and dynamic simulations.PC and TA could bind with CEase and inhibit the activity of enzyme in a mixed-competitive manner and non-competitive manner,which was verified by molecular docking simulations and dynamics simulations.Also,PC and TA showed the synergistic inhibition with orlistat.Fluorescence,UVvis and the thermodynamic analysis revealed that the complexes were formed from CEase and inhibitors by noncovalent interaction.As revealed by the circular dichroism results,both PC and TA decreased enzymatic activities by altering the conformations of CEase.The inhibition of PC and TA on CEase might be one mechanism for its cholesterol-lowering effect.展开更多
EST isozymes are one of the frequently used biochemical markers in genetic analysis of fungi. and the staining is an important process in electrophoresis analysis of studying Est.The effects were compared ainong diff...EST isozymes are one of the frequently used biochemical markers in genetic analysis of fungi. and the staining is an important process in electrophoresis analysis of studying Est.The effects were compared ainong different stain recipes for Est of 3 kinds of fungi-Lentinus edodes. Pleurotus sapidus. Phellinus igriarius and 2 kinds of plants-Populus sp and Brassica chinensis. Of the four kinds of Est staining recipes tested.the recipe α-acetic acid-naphther showed the best effect.and followed by β-aceticacid-naphther, semicontent α-aceticacid-naphther and α+β-aceticacidnathpher.展开更多
Three organophosphate resistant strains (FS-1, FS-2 and CD-1) with different esterase patterns were selected from collections of Culex quinquefasciatus from Foshan and Chengdu, China. The numbers of esterase B gene co...Three organophosphate resistant strains (FS-1, FS-2 and CD-1) with different esterase patterns were selected from collections of Culex quinquefasciatus from Foshan and Chengdu, China. The numbers of esterase B gene copies were approximately 32-fold in FS-1, 8￣16-fold in FS-2 and 2￣4-fold in CD-1. The amplification levels of esterase B genes were correlated with esterase activities and organophosphate resistances among the three strains. The restriction pattern comparison of the amplified region containing the esterase B gene revealed large differences between these strains. The esterase B1 was found in FS-1, and two esterases, B2 and a new B haplotype (named B6), were detected in FS-2. Another new haplotype (named B7) was observed in CD-1. The esterases B6 and B7 had identical electrophoretic mobility, but had different restriction patterns within the regions flanking the esterase B gene, indicating that two distinct haplotypes have been amplified independently in Culex populations from Foshan and Chengdu, China.展开更多
Quorum sensing(QS)system can dynamically control the expression of proteins along with the cell growth.The promoting period of QS system has been little focused on until now.In this study,a self-induced dynamic regula...Quorum sensing(QS)system can dynamically control the expression of proteins along with the cell growth.The promoting period of QS system has been little focused on until now.In this study,a self-induced dynamic regulated expression(SIDRE)system was constructed in Escherichia coli.To enable the system suitable for the expression of enzymes,promoter engineering was used to obtain P_(luxI)mutants.To test the SIDRE system,alginate lyase AL493 and esterase Est7 were used as target protein for expression.The enzyme activity of alginate lyase and esterase reached 96.38%and 106.71%of the control strains containing the T7 promoter.In high-density fermentation,the activity of alginate lyase expressed by the SIDRE system with P_(luxI)(T-38C)as promoter was 4.34-fold of that expressed by the T7 promoter.Therefore,the P_(luxI)mutants with different promoting periods and/or different strengths show great potential in both laboratory and industrial scale for protein expression.展开更多
Hereditary angioedema （HAE） is an autosomal dominant condition that affects one in about 50 000 persons, characterized by recurrent episodes of subcutaneous or submucosal swelling involving the hands, feet, limbs, f...Hereditary angioedema （HAE） is an autosomal dominant condition that affects one in about 50 000 persons, characterized by recurrent episodes of subcutaneous or submucosal swelling involving the hands, feet, limbs, face, intestinal tract, even larynx and trachea.展开更多
基金supported by the National Basic Research Program of China(‘973’program,2013CB127106)。
文摘This study was aimed to analyze the effect of procyanidin B2(PC)and tannin acid(TA)on the activities of cholesterol esterase(CEase)and the inhibitory mechanisms of enzymatic activity.The interaction mechanisms were investigated by enzymatic kinetics,multi-spectroscopy methods,thermodynamics analysis,molecular docking,and dynamic simulations.PC and TA could bind with CEase and inhibit the activity of enzyme in a mixed-competitive manner and non-competitive manner,which was verified by molecular docking simulations and dynamics simulations.Also,PC and TA showed the synergistic inhibition with orlistat.Fluorescence,UVvis and the thermodynamic analysis revealed that the complexes were formed from CEase and inhibitors by noncovalent interaction.As revealed by the circular dichroism results,both PC and TA decreased enzymatic activities by altering the conformations of CEase.The inhibition of PC and TA on CEase might be one mechanism for its cholesterol-lowering effect.
文摘EST isozymes are one of the frequently used biochemical markers in genetic analysis of fungi. and the staining is an important process in electrophoresis analysis of studying Est.The effects were compared ainong different stain recipes for Est of 3 kinds of fungi-Lentinus edodes. Pleurotus sapidus. Phellinus igriarius and 2 kinds of plants-Populus sp and Brassica chinensis. Of the four kinds of Est staining recipes tested.the recipe α-acetic acid-naphther showed the best effect.and followed by β-aceticacid-naphther, semicontent α-aceticacid-naphther and α+β-aceticacidnathpher.
文摘Three organophosphate resistant strains (FS-1, FS-2 and CD-1) with different esterase patterns were selected from collections of Culex quinquefasciatus from Foshan and Chengdu, China. The numbers of esterase B gene copies were approximately 32-fold in FS-1, 8￣16-fold in FS-2 and 2￣4-fold in CD-1. The amplification levels of esterase B genes were correlated with esterase activities and organophosphate resistances among the three strains. The restriction pattern comparison of the amplified region containing the esterase B gene revealed large differences between these strains. The esterase B1 was found in FS-1, and two esterases, B2 and a new B haplotype (named B6), were detected in FS-2. Another new haplotype (named B7) was observed in CD-1. The esterases B6 and B7 had identical electrophoretic mobility, but had different restriction patterns within the regions flanking the esterase B gene, indicating that two distinct haplotypes have been amplified independently in Culex populations from Foshan and Chengdu, China.
基金supported by the National Natural Science Foundation of China(31922072)Natural Science Foundation of Shandong Province(ZR2020JQ15)+3 种基金Project of Shandong Province Higher Educational Science and Technology Program(2019KJF012)Taishan Scholar Project of Shandong Province(tsqn201812020)China Agriculture Research System(CARS-48)Qingdao Science and Technology Demonstration and Guidance Project for Benefiting the People(20-3-4-28-nsh)。
文摘Quorum sensing(QS)system can dynamically control the expression of proteins along with the cell growth.The promoting period of QS system has been little focused on until now.In this study,a self-induced dynamic regulated expression(SIDRE)system was constructed in Escherichia coli.To enable the system suitable for the expression of enzymes,promoter engineering was used to obtain P_(luxI)mutants.To test the SIDRE system,alginate lyase AL493 and esterase Est7 were used as target protein for expression.The enzyme activity of alginate lyase and esterase reached 96.38%and 106.71%of the control strains containing the T7 promoter.In high-density fermentation,the activity of alginate lyase expressed by the SIDRE system with P_(luxI)(T-38C)as promoter was 4.34-fold of that expressed by the T7 promoter.Therefore,the P_(luxI)mutants with different promoting periods and/or different strengths show great potential in both laboratory and industrial scale for protein expression.
文摘Hereditary angioedema （HAE） is an autosomal dominant condition that affects one in about 50 000 persons, characterized by recurrent episodes of subcutaneous or submucosal swelling involving the hands, feet, limbs, face, intestinal tract, even larynx and trachea.
