Inhibition of Branched-Chain α-Ketoacid Dehydrogenase Kinase by Thiamine Pyrophosphate at Different Potassium Ionic Levels

Keiichi AKITA; Yukihiro FUJIMURA; Gustavo BAJOTTO; Yoshiharu SHIMOMURA

doi:10.1271/bbb.80749

This article has now been updated. Please use the final version.

Inhibition of Branched-Chain α-Ketoacid Dehydrogenase Kinase by Thiamine Pyrophosphate at Different Potassium Ionic Levels

Keiichi AKITA, Yukihiro FUJIMURA, Gustavo BAJOTTO, Yoshiharu SHIMOMURA

Author information

Keywords: branched-chain α-ketoacid dehydrogenase kinase, thiamine pyrophosphate, enzyme inhibitor, IC₅₀, inhibition constant

JOURNAL FREE ACCESS Advance online publication

Article ID: 80749

DOI https://doi.org/10.1271/bbb.80749

The final version of this article is now available: Vol. 73 (2009) , No. 5 p.1189

Details

Abstract

Inhibition of branched-chain α-ketoacid dehydrogenase kinase (BDK) by thiamine pyrophosphate (TPP) was analyzed at two potassium ion (K⁺) concentrations. IC₅₀ values of 4.6 and 8.0 μM and inhibition constant values of 3.2 and 16.4 μM were obtained in the presence of 20 and 100 mM K⁺, respectively. These results suggest that BDK is less sensitive to TPP inhibition under physiological TPP and K⁺ concentrations.

Corresponding author

Register with J-STAGE for free!