Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9745104 | Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics | 2005 | 9 Pages |
Abstract
A thermostable alkaline phosphatase with high specific activity and thermal resistance was purified from a novel species of Thermus sp. named as Thermus yunnanensis sp. nov. The enzyme contains a single peptide with a molecular mass of about 52 kDa on SDS-PAGE analysis and appears to be a homodimer in solution with the molecular mass of 104 kDa. The optimal pH and temperature for its activities are pH 8.0-10.0 and 70-80 °C, respectively. The catalytic activities of the enzyme are metal ion dependent, and Mg2+, Zn2+ and Co2+ are the main activators. Among these, Co2+ is the most active stimulator and has unique activation effect at high temperature. Metal binding analysis showed the binding of Mg2+ at the metal binding site was easy to loss in the thermoinactivation, and Co2+ was apt to bind at that site and kept the favorable configuration of catalysis, which would result high activation in the incubation with Co2+ at high temperature. According to this study, a model was proposed for the explanation of the activation and the results of actual experiments demonstrated the validity of the model.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Ningping Gong, Chaoyin Chen, Liping Xie, Hongtao Chen, Xianzhi Lin, Rongqing Zhang,