Marcel Bokhove, Takashi Kawamura, Hideo Okumura, Sawako Goto, Yoshiaki Kawano, Stefan Werner, Franziska Jarczowski, Victor Klimyuk, Akihiko Saito, Takashi Kumasaka
Vitamin B12 (cobalamin or Cbl) functions as a cofactor in two important enzymatic processes in human cells, and life is not sustainable without it. B12 is obtained from food and travels from the stomach, through the intestine and into the bloodstream by three B12 -transporting proteins: salivary haptocorrin (HC), gastric intrinsic factor (IF) and transcobalamin (TC), which all bind B12 with high affinity and require proteolytic degradation to liberate Cbl. After intracellular delivery of dietary B12 , Cbl in the aquo/hydroxo-Cbl (HOCbl) form can coordinate various nucleophiles, e...
April 16, 2024: Journal of Biological Chemistry