Regulation of pyridoxal 5′-phosphate metabolism in liver

Journal Article

The pyridoxal 5′-phosphate content of liver in vivo and of hepatocytes in vitro remains unaltered in the presence of excess unphosphorylated vitamin B6 precursors. Studies with isolated hepatocytes and subcellular fractions show that while product inhibition of pyridoxine phosphate oxidase does not limit synthesis sufficiently to account for the phenomenon, inhibition of phosphatase activity produces striking increases in pyridoxal 5′-phosphate concentration. Protein-binding protects it against degradation by the phosphatase. The data suggest that protein-binding and the enzymatic hydrolysis of pyridoxal 5′-phosphate, synthesized in excess, act jointly to preserve the constancy of the cellular content of this coenzyme. © 1974.

Cited Authors

  • Li, TK; Lumeng, L; Veitch, RL

Published Date

  • 1974

Published In

Volume / Issue

  • 61 / 2

Start / End Page

  • 677 - 684

International Standard Serial Number (ISSN)

  • 0006-291X