【摘要】 将两类水难溶性金属卟啉(MP),meso-四苯基卟啉金属配合物(MTPP,M=ZnII,CoII)和meso-四(p-羟基苯基)卟啉金属配合物(MTpHPP,M=ZnII,CoII)分别与牛血清白蛋白(BSA)结合,制得水溶性金属卟啉白蛋白结合体(MP@BSA).采用UV-vis光谱、聚丙烯酰胺凝胶电泳(PAGE)、圆二色谱进行了表征与分析,发现金属卟啉的水溶性和稳定性得到大幅度提高.采用NBT光还原法测定了MP@BSA结合体清除超氧阴离子自由基(O2·-)的能力,发现结合体MP@BSA具有清除O2·-的性能,与小分子金属卟啉相比,结合体的抗O2·-性能提高了一个数量级.MP@BSA抗氧化活性分别是VC和BSA的600倍和40倍.其中,羟基取代金属卟啉结合体表现出更强的清除O2·-的活性,CoTpHPP@BSA的EC50为1.5μmol/L,对天然Cu,Zn-SOD的模拟度为2.73%.最后提出了生物高分子结合体清除O2·-的可能机理.更多还原

【Abstract】 In this work,two kinds of water-insoluble metalloporphyrin(MP),meso-tetraphenylporphyrin metal complexes(MTPP,M:ZnII,CoII) and meso-tetra(p-hydroxylphenyl)porphyrin metal complexes(MTpHPP,M:ZnII,CoII),were combined into bovine serum albumin(BSA),a kind of stable and soluble biopolymer.The obtained water-soluble metalloporphyrin at BSA conjugates(MP@BSA) have been characterized by UV-vis spectra,PAGE gel electrophoresis and circular dichroism spectra.It indicated that the water-solubility and stability of metalloporphyrins were significantly increased after being bound into bovine serum albumin.Their SOD-like activities for scavenging superoxide anion free radical(O2·-) were determined by NBT assay and compared with natural antioxidant.The activities of MP@BSA were more decuple than that of metalloporphyrins.The EC50 values of MP@BSA were 600-fold and 40-fold higher than that of Vitamin C(VC) and BSA,respectively.The hydroxyl substituted metalloporphyrin showed more active than that of MTPP,and EC50 of CoTpHPP@BSA got to 1.5μmol/L.Compared with natural Cu,Zn-SOD,the analog quantity of CoTpHPP@ BSA reached 2.73%.更多还原