Structure, function, and molecular evolution of vitamin B_6-dependent enzymes

DOI Web Site
  • Yoshimura Tohru
    Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University

Bibliographic Information

Other Title
  • ビタミンB_6酵素の構造,機能,進化に関する研究
  • ビタミン B ₆ コウソ ノ コウゾウ,キノウ,シンカ ニ カンスル ケンキュウ

Search this article

Abstract

The reaction mechanism of vitamin B_6 (pyridoxal 5'-phosphate)-dependent enzymes involved in the amino acid metabolism have been studied for over 60 years. Some of our contributions to this scientific field have been introduced in this review. This review has focused on the stereospecificity for the proton transfer between Cα of the substrate amino acid and C4' of the cofactor upon the half transamination catalyzed by various pyridoxal enzymes. We found the enzymes that catalyze the C-4' pro-R hydrogen transfer and the C-4' pro-S and pro-R hydrogen transfer for the first time. We confirmed that the stereospecificty is related to the structure and molecular evolution of the enzymes. Now, D-Amino acids such as D-serine and D-aspartate attract attention because of their physiological functions in the central nerve system and so on. We compared the reaction mechanism of pyridoxal 5'-phosphate-dependent alanine racemase and serine racemase, which are responsible for the de novo synthesis of D-amino acids. Both enzyme reactions proceed through a similar two-base mechanism, though the enzymes are structurally and evolutionally different. We found a novel D-serine dehydratase, which is a pyridoxal enzyme and responsible for D-serine degradation in vertebrates except mammals. The structure, function, and application of the enzyme have also been introduced in this review.

Journal

  • VITAMINS

    VITAMINS 89 (7), 327-340, 2015

    THE VITAMIN SOCIETY OF JAPAN

Keywords

Details 詳細情報について

Report a problem

Back to top