Identification of the calmodulin-binding domain of skeletal muscle myosin light

Update item information
Publication Type Journal Article
School or College College of Pharmacy; School of Medicine
Department Biomedical Informatics; Biochemistry; Pharmacology & Toxicology
Creator Blumenthal, Donald K.
Other Author Takio, Koiti; Edelman, Arthur M.; Charbonneau, Harry; Titani, Koji; Walsh, Kenneth A.; Kregs, Edwin G.
Title Identification of the calmodulin-binding domain of skeletal muscle myosin light
Date 1985-05
Description In the course of determining the primary structure of rabbit skeletal muscle myosin light chain kinase (MLCK; ATP:protein phosphotransferase, EC a peptide fragment was obtained that appears to represent the calmodulin-binding domain of this enzyme. Low concentrations of the peptide inhibited calmodulin activation of MLCK (Ki congruent to 1 nM). The peptide was not associated with a catalytically active, calmodulin-independent form of MLCK that was obtained by limited proteolysis. The peptide is 27 residues in length and represents the carboxyl terminus of MLCK. The sequence of the peptide shows no significant homology with any known protein sequence. The peptide contains one tryptophanyl residue and a high percentage of basic and hydrophobic residues, but no acidic or prolyl residues. Much of the sequence has a high probability of forming alpha helix. A chemically synthesized peptide has been prepared to study the interactions of the peptide and calmodulin in more detail. The intrinsic tryptophan fluorescence of the synthetic peptide shows a significant enhancement (approximately equal to 45%) in the presence of Ca2+ and calmodulin; fluorescence enhancement is maximal at a peptide:calmodulin stoichiometry of 1:1. Calmodulin-Sepharose affinity chromatography in the presence of 2 M urea indicates that the interaction of peptide and calmodulin is Ca2+-dependent. The results of these studies indicate that the catalytic and calmodulin-binding domains of MLCK represent distinct and separable regions of the protein. In addition, the results provide a basis for future studies of the molecular and evolutionary details of calmodulin-dependent enzyme regulation.
Type Text
Publisher National Academy of Sciences
Volume 82
Issue 10
First Page 3187
Last Page 3191
Subject Peptides; Enzymes; Protein sequence
Subject MESH Binding, Competitive; Calmodulin; Protein Kinases; Peptide Fragments; Myosin-Light-Chain Kinase; Protein Kinases; Tryptophan; Spectrometry, Fluorescence
Language eng
Bibliographic Citation Blumenthal DK, Takio K, Edelman AM, Charbonneau H, Titani K, Walsh KA, Krebs EG. Identification of the calmodulin-binding domain of skeletal muscle myosin light. Proc Natl Acad Sci U S A. 1985 May;82(10):3187-91. Retrieved August 31, 2006 from
Rights Management Copyright © National Academy of Sciences, Proc Natl Acad Sci., 82, 3187-91, 1985.
Format Medium application/pdf
Identifier ir-main,362
ARK ark:/87278/s6hx1wrg
Setname ir_uspace
Date Created 2012-06-13
Date Modified 2021-05-06
ID 702629
Reference URL
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