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1、榊皮素与人血清白蛋白作用机理王欢王姣蒲小华李宗孝宝鸡文理学院化学化工学院陕西省植物化学重点实验室摘要:采用荧光光谱、紫外吸收光谱、分子模拟等技术,研究了榊皮素与人血清口蛋口(HSA)相互作用的热力学行为。荧光实验结果表明:桝皮素与HSA相互作用时,随着榊皮素的浓度从0增加到1.962X10_6mol/L,HAS的荧光强度从844.3下降到461.4,最大发射波长由340.7nm降低到338.6nm,变化不明显,并且随着温度从293K升高到303K,猝灭常数由4.66X105L/mol减小到2.69X105L/mol,说明桝皮素对IISA的内源荧光有明显的猝
2、灭作用,猝灭机理为静态猝灭。分子模拟结果显示:榊皮素分子在HAS的SudlowI位点和SudlowII位点的结合最高积分分别为6.41和7.36,总能量分别为-37・01kJ/mol和-39.98kJ/mol,表明其在SudlowII位点的结合能力较强,•且两种结合的作用力主要为氢键作用(键能分别为-10.41kJ/mol和-12.34kJ/mol)。在位点I和位点II上,榊皮素分子与发光氨基酸残基Trp214的质心距离分别为1・36和2.40nm。这与根据F9rster,s非辐射能量转移理论计算的平均距离3.04nm结果基本吻合。关键词:人血清白蛋白;荧
3、光光谱;分了模拟技术;桝皮素;静态猝灭;医药原料;作者简介:王欢(1991—),男,硕士生。作者简介:李宗孝,教授,E-ma订:mingtian8001@163.com0收稿日期:2017-06-09基金:陕西省重点实验室项目(12JS006)TheMechanismbetweenQuercetinandHumanSerumAlbuminWANGHuonWANGJiaoPUXiao—huaLIZong—xiaoShaanxiKeyLaboratoryofPhytochemistry,BaojiUniversityofArtsandSciences;Abst
4、ract:Thethermodynamicbehaviorofinteractionbetweenquercetinandhumanserumalbumin(HSA)wasinvestigatedbyfluorescencespectroscopy(FS),UV-visabsorptionandmolecularsimulation(MS)techniques.Thefluoresceneeexperimentsshowedthatwhentheconcentrationofquercetinincreasedfrom0to1・962X10bmol/L,t
5、hefluorescenccintcnsityofHASdecreasedfrom844.3to461.4,andthemaximumemissionwavelengthdecreasedfrom340.7nmto338.6nmwithoutobviouschange.Andwhentemperatureincreasedfrom293Kto303K,thequenchingconstantdecreasedfrom4.66X10°L/molto2.69X10"L/mol,indicatingthatthefluorescencequenchingofUS
6、Abyadditionofqucrcctinwasduetostaticquenching.Inmolecularsimulationexperiments,thehighestpointofquercetinmoleculebindingtoSudlow,ssitesIandIIofHSAwas6.41and7.36,respectively,andthecorrespondingtotalenergywas-37.01kJ/moland~39.98kJ/mol,respectively,showingthattheassociationforqucrc
7、ctinbindingtositeIIofUSAwasstrongcr.Furthcnnorc,thetwoforcesofassociationweremainlyhydrogenbondinginteractions(bondenergieswere-10.41kJ/moland-12.34kJ/mol,respectively).ThedistancesfromquercetintothecenterpositionoffluorescentaminoacidresiduesTrp214onthesitesIandIIwere1.36and2.40n
8、m,whichwereinagrecmentwiththedist