Primary structure required for the inhibition of smooth muscle myosin light chain kinase

Publisher Website
Google Scholar
Abstract
Myosin light chain kinase (MLCK) contains the autoinhibitor sequence right next to the N‐terminus side of the calmodulin binding region. In this paper, the structural requirement of the inhibition of MLCK activity was studied using synthetic peptide analogs. Peptides Ala‐783‐Lys‐799 and Ala‐783‐Arg‐798 inhibited calmodulin independent MLCK at the same potency as the peptide Ala‐783–Gly‐804. Deletion of Arg‐797‐Lys‐799 or substitution of these residues to Ala markedly increased the K i while the substitution of Lys‐792 and Lys‐793 to Ala and the deletion of Lys‐784‐Lys‐785 did not affect the inhibitory activity of the peptides. The results suggest that Arg‐797‐Arg‐798 are especially important for the inhibitory activity among other basic residues in the autoinhibitory region.