The Role of Propeptide in the Refolding of Human Group IB Phospholipase A_2  

作　　者：Hong-QiangCHENG] Gen-JunXU 

机构地区：[2]InstituteofBiochemistryandCellBiology,ShanghaiInstitutesforBiologicalSciences,ChineseAcademyofSciences,Shanghai200031,China [3]CollegeofLifeScience,ZhejiangUniversityofSciences,Hangzhou310033,China

出　　处：《Acta Biochimica et Biophysica Sinica》2004年第9期583-588,共6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 ScienceFoundation of China (No. 39930060)

摘　　要：Human group IB phospholipase A2 (IB-PLA2) and its zymogen (proIB-PLA2) were purified from E. coli. Refolding was carried out by diluting the denatured forms of both IB-PLA2 and proIB-PLA2 with renaturation buffer in which the disulfide bonds were completely reduced. The refolding yield of proIB-PLA2 was increased by about 50% over that of the mature enzyme. The refolding of IB-PLA2 usually produced aggregates under normal conditions, as determined by light scattering. In addition, the unfolding experiments showed that the mature enzyme was more stable than the proenzyme toward denaturants in the presence of DTT. Results suggested that the N-terminal sequence rather than its conformation of human proIB-PLA2 played an important role in the refolding process.Human group IB phospholipase A2 (IB-PLA2) and its zymogen (proIB-PLA2) were purified from E. coli. Refolding was carried out by diluting the denatured forms of both IB-PLA2 and proIB-PLA2 with renaturation buffer in which the disulfide bonds were completely reduced. The refolding yield of proIB-PLA2 was increased by about 50% over that of the mature enzyme. The refolding of IB-PLA2 usually produced aggregates under normal conditions, as determined by light scattering. In addition, the unfolding experiments showed that the mature enzyme was more stable than the proenzyme toward denaturants in the presence of DTT. Results suggested that the N-terminal sequence rather than its conformation of human proIB-PLA2 played an important role in the refolding process.

关 键 词：human group IB phospholipase A2 (IB-PLA2) REFOLDING first disulfide bond PROPEPTIDE 

分 类 号：Q55[生物学—生物化学]