摘要
采用紫外光谱 (UV -spectrum)、荧光光谱 (fluorescencespectrum)以及红外光谱 (FT -IRspectrum)分析了SAPP以及其MTGase -聚合物的结构特征。紫外光谱结果显示MTGase催化SAPP导致它的多肽链的侧链结构发生了变化 ,Tyr和Trp残基的吸收峰红移说明其Cα原子的构型从非平面型转变为平面型 ,而荧光光谱显示MTGase催化导致SAPP的疏水区域暴露出来 ,而且还经历一个空间结构重排的过程 ,而红外光谱显示这种聚合作用还导致多肽链的二级结构发生较大的变化 ,即一部分的 β -折叠二级结构转变为以α -螺旋或无规卷曲。从蛋白质分子结构的角度 ,探讨了MTGase聚合SAPP的改性机理 ,指出其机理在于MTGase聚合导致了SAPP的空间结构发生了变化的缘故。
The molecular structural features of SAPP and its MTGase-polymerized biopolymers were analyzed through UV-,fluorescence and IR- spectrums. The results of UV-spectrum indicated that the side chain structures of peptides of SAPP were changed,and the conformation of Cα was changed from “non-plane”to“plane”. The fluorescence spectrum of SAPP indicated that the hydrophobic areas of peptide of SAPP became more exposed and SAPP underwent a course of rearrangement of spatial structure after SAPP was polymerized by MTGase. And FT-IR spectrum indicated that the secondary structures of peptides were changed from β-sheet to α-coil or random coil. The modifying mechanism of SAPP polymerized by MTGase was investigated accordingly to protein molecular structure.It is pointed out that the mechanism of modification of SAPP by MTGase is due to the changes of molecular structures induced by MTGase polymerization.
出处
《中国粮油学报》
EI
CAS
CSCD
北大核心
2004年第3期42-46,共5页
Journal of the Chinese Cereals and Oils Association
基金
国家自然科学基金项目 (2 0 30 60 0 8)
广东省"十五"农产品加工重大专项 (A2 0 30 1 )
华南理工大学自然科学基金 (E52 760 )资助
