Effects of Denaturation and Amino Acid Modification on Fluorescence Spectrum and Hemagglutinating Activity of Hericium erinaceum Lectin  

作　　者：MengGONG JieAN Hong-ZhouLü Chuan-FangWU Yi-JinLI Jing-QiuCHENG Jin-KuBAO 

机构地区：[1]CollegeofLifeSciences,SichuanUniversity,Chengdu610064,China

出　　处：《Acta Biochimica et Biophysica Sinica》2004年第5期343-350,共8页生物化学与生物物理学报（英文版）

基　　金：This work was supported by a grant from the National Natural Science Foundation of China (General Program) (No. 30000032)

摘　　要：A sialic acid-binding lectin (Hericium erinaceum lectin, HEL), isolated from fresh fruiting bodies of Hericium erinaceum, was treated with various temperature and pH to investigate its fluorescence spectra and hemagglutinating activity. It was found that the hemagglutinating activity of HEL was relatively steady below 60 °C and at pH from 6 to 11, and the change of hemagglutinating activity was relative to the change of hydrophobic areas where tryptophan residues located. In fluorescence quenching study of HEL by acrylamide and KI, it was indicated that nearly all the tryptophan residues of HEL located on the surface of the molecule, and most of them were in hydrophobic areas or negatively charged areas. Chemical modifica- tion of HEL proved that there were about twelve tryptophan residues in a HEL molecule and all of them were located on the surface or in the shallow groove of the molecule, and eight of them were essential for hemag- glutinating activity; aspartic acid or glutamic acid residues were involved in maintaining the crucial confor- mation of activity center and made great contribution to the hemagglutinating activity of HEL, but they could not touch the sialic acid molecule directly; tyrosine residues also played a role in the hemagglutinating activ- ity of HEL; while arginine, serine, threonine, histidine residues had no effect on the hemagglutinating activity of HEL.A sialic acid-binding lectin (Hericium erinaceum lectin, HEL), isolated from fresh fruiting bodies of Hericium erinaceum, was treated with various temperature and pH to investigate its fluorescence spectra and hemagglutinating activity. It was found that the hemagglutinating activity of HEL was relatively steady below 60 °C and at pH from 6 to 11, and the change of hemagglutinating activity was relative to the change of hydrophobic areas where tryptophan residues located. In fluorescence quenching study of HEL by acrylamide and KI, it was indicated that nearly all the tryptophan residues of HEL located on the surface of the molecule, and most of them were in hydrophobic areas or negatively charged areas. Chemical modifica- tion of HEL proved that there were about twelve tryptophan residues in a HEL molecule and all of them were located on the surface or in the shallow groove of the molecule, and eight of them were essential for hemag- glutinating activity; aspartic acid or glutamic acid residues were involved in maintaining the crucial confor- mation of activity center and made great contribution to the hemagglutinating activity of HEL, but they could not touch the sialic acid molecule directly; tyrosine residues also played a role in the hemagglutinating activ- ity of HEL; while arginine, serine, threonine, histidine residues had no effect on the hemagglutinating activity of HEL.

关 键 词：sialic acid-binding lectin Hericium erinaceum lectin fluorescence spectrum and fluores-      cence quenching hemagglutinating activity chemical modification 

分 类 号：Q51[生物学—生物化学]