Báo cáo khoa học: Properties of the recombinant glucose⁄galactose dehydrogenase from the extreme thermoacidophile, Picrophilus torridus

Properties of the Recombinant Glucose/Galactose Dehydrogenase from the Extreme Thermoacidophile, Picrophilus torridus

Tác giả: Angel Angelov, Ole Fütterer, Oliver Valerius, Gerhard H. Braus and Wolfgang Liebl

Lĩnh vực: Microbiology and Genetics, University of Goettingen, Germany

Nội dung tài liệu: This study focuses on the isolation, cloning, and characterization of the glucose dehydrogenase (GdhA) enzyme from the extreme thermoacidophile Picrophilus torridus. The research details the successful expression of the recombinant GdhA in Escherichia coli and its subsequent purification. The study investigates the enzyme’s substrate specificity, revealing its activity with both glucose and galactose, and its preference for NADP+ over NAD+ as a coenzyme. Physicochemical properties, including optimal pH and temperature, were determined. Notably, the research highlights the critical role of zinc ions in stabilizing GdhA, particularly under the harsh acidic and high-temperature conditions characteristic of P. torridus‘s environment. The instability of NADPH, a product of the GdhA reaction, under these physiological conditions is also discussed, suggesting a rapid turnover rate within the organism.

Mục lục chi tiết:

• Introduction
• Results
• Analysis of the amino acid sequence
• Cloning and expression of the P. torridus glucose dehydrogenase gene
• Purification and characterization of the recombinant glucose dehydrogenase
• Effect of temperature and pH on the stability of NADPH
• Identification of the native glucose dehydrogenase in P. torridus
• Discussion
• Experimental procedures
• Strains and growth conditions
• Cloning of the P. torridus glucose dehydrogenase gene and expression in E. coli
• Purification of P. torridus glucose dehydrogenase
• Assay for glucose dehydrogenase activity and enzyme kinetics
• Mass spectroscopy and protein identification
• References