Effect of pH on the Hydrolytic Kinetics of Gamma-Glutamyl Transferase from Bacillus subtilis
Joint Authors
Balakrishna, Sharath
Prabhune, Asmita
Source
Issue
Vol. 2014, Issue 2014 (31 Dec. 2014), pp.1-6, 6 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2014-02-24
Country of Publication
Egypt
No. of Pages
6
Main Subjects
Medicine
Information Technology and Computer Science
Abstract EN
The effect of pH on the steady state kinetics of gamma-glutamyl transferase (GGT) from Bacillus subtilis was examined using glutamyl-(3-carboxyl)-4-nitroanilide as the chromogenic reporter substrate.
The enzyme was active in the pH range 7.0–11.0 with the optimum activity at pH 11.0.
We noticed a pH dependent transformation in the nature of substrate consumption kinetics.
The substrate saturation curves were hyperbolic in the pH range 7.0–9.0 but changed into sigmoid form at pH 10.0 and 11.0.
Hill’s coefficients were >1.
We also analysed the effect of pH on the structure of the enzyme.
The circular dichroism spectra of the enzyme sample at pH 9.0 and 11.0 were coincidental in both far and near UV regions indicating conservation of the secondary and tertiary structures, respectively.
The molecular weight of the enzyme sample was the same in both pH 7.0 and 11.0 indicating conservation of the quaternary structure.
These results show that the kinetic transformation does not involve significant conformational changes.
Cooperative binding of multiple substrate molecules may not be the basis for the sigmoid kinetics as only one substrate binding site has been noticed in the reported crystal structures of B.
subtilis GGT.
American Psychological Association (APA)
Balakrishna, Sharath& Prabhune, Asmita. 2014. Effect of pH on the Hydrolytic Kinetics of Gamma-Glutamyl Transferase from Bacillus subtilis. The Scientific World Journal،Vol. 2014, no. 2014, pp.1-6.
https://search.emarefa.net/detail/BIM-1048776
Modern Language Association (MLA)
Balakrishna, Sharath& Prabhune, Asmita. Effect of pH on the Hydrolytic Kinetics of Gamma-Glutamyl Transferase from Bacillus subtilis. The Scientific World Journal No. 2014 (2014), pp.1-6.
https://search.emarefa.net/detail/BIM-1048776
American Medical Association (AMA)
Balakrishna, Sharath& Prabhune, Asmita. Effect of pH on the Hydrolytic Kinetics of Gamma-Glutamyl Transferase from Bacillus subtilis. The Scientific World Journal. 2014. Vol. 2014, no. 2014, pp.1-6.
https://search.emarefa.net/detail/BIM-1048776
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1048776