应用光亲和分子进行PEG的光照修饰及蛋白质的光照偶联

PEG MODIFICATION AND PROTEIN CONJUGATION BY VIRTUE OF 4-AZIDOBENZOIC ACID AS A PHOTOAFFINITY MOLECULE

合成了一种光活性标记分子-对叠氮苯甲酸,将其偶联到具有双羟基的碳酸酯与乳酸的共聚物P(LA-co-DHP)上,获得了具有光反应活性的可生物降解共聚物P(LA-co-DAP),在光照条件下,可以将蛋白质方便快捷地共价偶联到P(LA-co-DHP)聚合物纤维上.在溶液中进行PEG与对叠氮苯甲酸的光照反应,通过核磁共振光谱检测,证明了对叠氮苯甲酸可以直接修饰到PEG侧链上,形成苯甲酸侧基PhCOOH.这是其它化学修饰方法很难做到的.实验还证明,对叠氮苯甲酸对PEG的光亲和修饰不但能在溶液中进行,而且能在PEG自组装膜的表面进行.

A photoaffinity labeling molecule,4-azidobenzoic acid,was synthesized and introduced into P（LA-co-DHP） to form a photoactive copolymer P（LA-co-DAP）.Tests showed that proteins could be immobilized on the polymer fibers of P（LA-co-DAP） within 5 min through a photoaffinity reaction.This suggested potential applications of photoaffinity coupling in protein immobilization and protein detection.Furthermore,PEG and 4-azidobenzoic acid were reacted in solution under UV irradiation to achieve the modification on PEG chains.The PEG molecules assembled on gold surface were reacted also with 4-azidobenzoic acid under UV irradiation.BSA adsorption test by FT-SPR showed that the 4-azidobenzoic acid moieties were successfully attached to the PEG segments so that the protein adsorption ability of the PEG surface was changed.In this way,functional groups like —PhCOOH were introduced onto PEG chains in a convenient and quick manner.This would offer a new method to achieve the modification of the polymers lacking of functional groups.