title: Primary structure required for the inhibition of smooth muscle myosin light chain kinase.
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 Ki 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.
authors.affiliation: Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106-4970.
authors.forename: M
authors.initials: M
authors.lastname: Ikebe
authors.forename: S
authors.initials: S
authors.lastname: Reardon
authors.forename: F S
authors.initials: FS
authors.lastname: Fay
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002147:Calmodulin / Q000378:metabolism; D002417:Cattle; D008297:Male; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000201:enzymology*; D009219:Myosin-Light-Chain Kinase / Q000037:antagonists & inhibitors* / Q000737:chemistry; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry; D014422:Turkeys
chemical_list: D002147:Calmodulin; D010446:Peptide Fragments; D009219:Myosin-Light-Chain Kinase