These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Ca2+-dependent inhibition of branched-chain α-ketoacid dehydrogenase kinase by thiamine pyrophosphate.
    Author: Noguchi S, Kondo Y, Ito R, Katayama T, Kazama S, Kadota Y, Kitaura Y, Harris RA, Shimomura Y.
    Journal: Biochem Biophys Res Commun; 2018 Oct 12; 504(4):916-920. PubMed ID: 30224059.
    Abstract:
    Catabolism of the branched-chain amino acids (BCAAs: leucine, isoleucine, and valine) is regulated by the branched-chain α-ketoacid dehydrogenase (BCKDH) complex, which in turn is regulated by phosphorylation catalyzed by BCKDH kinase (BDK). Thiamine pyrophosphate (TPP) is required as a coenzyme for the E1 component of the BCKDH complex and can also bring about activation of the complex by inhibiting BDK. The present study shows that free Ca2+ in the physiological range greatly increases the sensitivity of BDK to inhibition by TPP (IC50 of 2.5 μM in the presence of 1 μM free Ca2+). This novel mechanism may be responsible for the stimulation of BCAA oxidation by conditions that increase mitochondrial free Ca2+ levels, e.g. in skeletal muscle during exercise.
    [Abstract] [Full Text] [Related] [New Search]