期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1977
卷号:74
期号:2
页码:501-504
DOI:10.1073/pnas.74.2.501
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:A mutant pyruvate kinase (ATP:pyruvate 2-O-phosphotransferase, EC 2.7.1.40 ) from human erythrocytes which is easily separated into monomers and dimers by gel chromatography is described. Tht mutant enzyme shows almost the same pH optimum and thermostability as normal enzyme, but has a decreased stability on shaking with air, a decreased Km for phosphoenolpyruvate and a loss of allosteric properties. The apparent Km values for phosphoenolpyruvate of tetramers and monomers were the same. The tetrameric enzyme was slightly activated by fructose-1,6-diphosphate but the monomeric form was not. The tetrameric enzyme was found to dissociate spontaneously to dimeric and monomeric forms.