Nom du corpus

Corpus Systématique Animale

Titre du document

Amino acid sequences of myosin essential and regulatory light chains from two clam species: Comparison with other molluscan myosin light chains

Lien vers le document
Springer (journals)
Langue(s) du document
Type de document
Nom du fichier dans la ressource
  • Winifred W. Barouch 1
  • Kimberly E. Breese 1
  • Stephanie -Alexis Davidoff 2,3
  • John Leszyk 2,3
  • Andrew G. Szent-Györgyi 4
  • Janet L. Theibert 2,3
  • John H. Collins 2,3
  • 1) Departments of Chemistry and Biology, Clarkson University, 13676, Potsdam, New York, USA
  • 2) Department of Biological Chemistry, School of Medicine, USA
  • 3) Medical Biotechnology Center of the Maryland Biotechnology Institute, University of Maryland, 21201, Baltimore, Maryland, USA
  • 4) Department of Biology, Brandeis University, 02254, Waltham, Massachusetts, USA

We have determined the amino acid sequences of the essential light chains (ELC) and regulatory light chains (RLC) of myosin from two species of clam,Mercenaria mercenaria andMacrocallista nimbosa, using protein chemistry methods. The N-termini of all four proteins were blocked, and sequencing was carried out on various chemically and enzymatically produced peptide fragments. Cleavage of eitherMercenaria RLC (MRLC) orMacrocallista RLC (VLC) at its 3 Arg yielded four peptides, three of which could not be sequenced directly, due to an N-terminal blocking group and 2 Arg-Gln bonds in these proteins. The fourth peptide was partially and specifically cleaved at an unusually reactive residue, Met-64, which is invariant in all known RLC sequences. A comparison of all available molluscan ELC and RLC sequences was carried out in search of clues to functionally important features of these proteins in muscles which are regulated by a Ca2+-sensitive myosin. By analogy with other RLCs, VRLC and MRLC may be phosphorylated at Ser-11 by an endogenous kinase. All myosin light chains, like troponin C and calmodulin, contain four homologous regions, I to IV, each of which contains a twelve-residue potential Ca2+-binding loop flanked on either side by a pair of helices. All RLCs, including those from Ca2+-insensitive myosins, contain a divalent cation-binding site in region I. Clam and other molluscan ELCs contain a single Ca2+-binding site in region III. This site is present only in the ELCs of myosins that are regulated by direct binding of Ca2+. The ELC site III is likely to play a key role in the regulation of molluscan muscle contraction.

Catégories Science-Metrix
  • 1 - health sciences
  • 2 - biomedical research
  • 3 - physiology
Catégories INIST
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
  • 4 - vertebres: systeme cardiovasculaire
Catégories Scopus
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Cell Biology
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Biochemistry
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Physiology
Catégories WoS
  • 1 - science ; 2 - cell biology
Identifiant ISTEX

Journal of Muscle Research & Cell Motility

Année de publication
Présence de XML structuré
Version PDF
Score qualité du texte
  • Mollusques
Type de publication
Powered by Lodex 9.3.8