Studies on the kinetics and mechanism of orthophosphate activation of bovine brain hexokinase |
| |
Authors: | W R Ellison J D Lueck H J Fromm |
| |
Institution: | The Department of Biochemistry and Biophysics Iowa State University, Ames, Iowa 50010, USA |
| |
Abstract: | The binding of glucose to bovine brain hexokinase, isozyme I, exhibited one binding site per 100,000 molecular weight. Glucose-6-P binding was examined in the absence and presence of ATP. ATP and glucose-6-P were shown to compete for the same binding site on the enzyme. A model was proposed to account for these findings and the previously reported data that glucose-6-P and Pi exhibit mutually exclusive, non-cooperative binding to the enzyme. The model shows that brain hexokinase exists in two rapidly interconvertible states, either with or without Pi and that glucose-6-P binding to the phosphate associated enzyme form is relatively very poor. This proposal has been tested kinetically and the data appear to support the suggested model. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|