ИСТИНА

NAD+-dependent formate dehydrogenase (EC 1.2.1.2, FDH) plays important role in bacteria, yeasts, fungi and plants. In plants FDH is situated in mitochondria in contrast to cytoplasm localization in microorganisms. Plant FDH is the universal protein of stress. Under different stress conditions content of the enzyme sharply increased and could achieve up to 9% of total mitochondria proteins. Bioinformatic analysis showed that many plants have a few genes of FDH. In this report we will present data about study of two FDH - from Arabidopsis thaliana (AraFDH) and isoenzyme 2 from soya Glycine max (SoyFDH). cDNA of AraFDH and SoyFDH were optimized and cloned in E.coli cells. Both enzymes were expressed as soluble and active proteins with yield up to 1 g of target protein per L of cultivation medium. Kinetic properties and stability of AraFDH and SoyFDH were studied at different conditions. It was found that palnt FDHs show very high resistance to inactivation by hydrogen peroxide which is presented in mitochondria at high concentration under stress conditions. Crystallization of the enzymes were carried out on earth and in space. Crystal structures of apo- and holo-forms were solved with resolution till 1.4 angstrem. Rational design of the SoyFDH resulted in new mutants with higher specific activity, better Michaelis constants and great improvement of thermal stability. Common and characteristic features of properties and structures of microbial and plant FDHs are discussed. FEBS Journal, 2013, v.280, № S1, p.192.