Journal article
Yeast hexokinase. VI. Dissociation of yeast hexokinase under the influence of substrates
Biochemistry (Easton), Vol.11(10), pp.1793-1797
05/01/1972
DOI: 10.1021/bi00760a009
Abstract
A study by sedimentation equilibrium ultracentrifugation was made of the pure isoenzymes, B, and C, of yeast hexokinase, which can each form a reversibly dissociating system under nondenaturing conditions. The apparent molecular weight (Mipp) was determined, by computerized analysis, at points throughout the solution column in the cell, and hence related to varying protein concentration. By iterative fitting of curves based upon nonideal dissociation models, approximate values of the monomer-dimer association constants were estimated. The quantitative analysis showed that (at I = 0.15) there is no dissociation at pH 5.5, but that at pH 8 and above, dissociation is appreciable. Monomers of molecular weight 52, 000 and dimers of 104, 000 are the species involved. Dissociation is much augmented at higher ionic strengths. D-Glucose has a relatively small dissociating effect on native yeast hexokinase B, but this effect becomes large when a nucleotide substrate ADP (together with Mg2+) is present with the glucose. Neither d-glucose 6-phosphate nor D-galactose can replace glucose in the latter effect. It is concluded that dissociation of the native dimer of this enzyme is an important element in the catalysis. © 1972, American Chemical Society. All rights reserved.
Details
- Title: Subtitle
- Yeast hexokinase. VI. Dissociation of yeast hexokinase under the influence of substrates
- Creators
- Moises DerechinYoucef M RustumEric A Barnard
- Resource Type
- Journal article
- Publication Details
- Biochemistry (Easton), Vol.11(10), pp.1793-1797
- Publisher
- American Chemical Society
- DOI
- 10.1021/bi00760a009
- ISSN
- 0006-2960
- eISSN
- 1520-4995
- Language
- English
- Date published
- 05/01/1972
- Academic Unit
- Hematology, Oncology, and Blood & Marrow Transplantation; Internal Medicine
- Record Identifier
- 9984359890402771
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