【摘要】 利用脂质体的疏水微环境,完成了甘氨酸与磷酸吡哆醛的希夫碱反应。甘氨酸进行双烷基化修饰后,组装到脂质体中。利用肽脂质构建带正电荷的脂质体(pH=7.00),吸附带负电荷的磷酸吡哆醛,增强磷酸吡哆醛与脂质体上甘氨酸的伯胺基团作用,并通过脂质体疏水微环境促进脱水缩合过程。紫外光谱检测结果表明,单独的磷酸吡哆醛吸收峰为387 nm,吸附到脂质体后吸收峰红移到395 nm;当PLP与脂质体上甘氨酸反应转变为希夫碱后,最大吸收峰蓝移到336 nm;希夫碱结合铜离子后,最大吸收峰从336 nm再次红移,出现383 nm吸收峰。脂质体上新形成的希夫碱与乳酸脱氢酶竞争铜离子,解除铜离子对乳酸脱氢酶活性的抑制。更多还原

【Abstract】 The formation of Schiff base between the modified glycine and pyridoxal-5-phosphate(PLP) on liposome surface was investigated.In HEPES buffer(pH=7.00),the negative charged PLP was attracted by the positive charged head group of peptide lipid and anchored on liposome membrane surface,and then reacted with the amino group of the modified glycine on liposome surface.The UV absorption peak of PLP shifted from 387 nm to 395 nm,when PLP was attached to liposome surface.The absorption peak was changed to 336 nm(Schiff base) when PLP was reacted with the amino group in modified glycine which anchored on liposome membrane surface.Binding to Cu2+,the absorption peak of the Schiff base shifted to long wavelength(383 nm).The relative activity of the lactate dehydrogenase(LDH)was 23.3% due to the inhibition of Cu2+,but in creased to 92.8% in the presence of Schiff base.更多还原