ИСТИНА

NAD+-dependent formate dehydrogenase (EC 1.2.1.2, FDH) is widely occured in nature. Genes of FDH were found in many pathogens such as Staphylococcus aureus, Mycobacterium avium subsp. paratuberculosis str. k10, different strains of Bordetella and Legionella, Francisella tularensis subsp. tularensis SCHU S4, Histoplasma capsulatum, Cryptococcus neoformans var. neoformans JEC21, etc. The enzyme plays important role in these microorganisms. For example, in the case of S. aureus, FDH is one of three overexpressed proteins, when the bacterium grows at biofilm conditions [1]. Bacterial biofilm infections are particularly problematic because sessile bacteria can often withstand host immune responses and are generally much more tolerant to antibiotics, biocides, and hydrodynamic shear forces than their planktonic counterparts. Expression of FDH gene is also phase specific in fungal pathogens [1]. So, search and development of specific inhibitors of FDH in pathogens is promising way to create new drugs. We have cloned and expressed in E.coli gene of FDH from S. aureus. The enzyme was purified and studied. Data about catalytic properties and thermal stability will be presented. Other aspect of high practical interest of FDH is use in processes of sythesis of chiral compounds which are used as building blocks in many durgs. For this purpose we cloned and expressed in E.coli FDH from soya Glycine max. The enzyme shows the best Km values among all known FDHs. Protein engineering experiments resulted in increase of catalytic constant and thermal stability.