Caldesmon, acidic amino acids and molecular weight determinations.
Recent estimates of molecular weight and cDNA sequencing indicate that smooth muscle caldesmons are considerably smaller than previously thought. The anomalous behaviour of these proteins during SDS-polyacrylamide gel electrophoresis can be correlated with their high acidic amino acid content. The results suggest a need to re-evaluate the stoichiometric relations of caldesmon to tropomyosin and actin in thin filaments and its presumed 1:1 interaction with calmodulin.
Bryan
J
J
Baylor College of Medicine, Houston, Texas 77030.
D000596:Amino Acids / Q000032:analysis*; D002148:Calmodulin-Binding Proteins / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D006801:Humans; D008970:Molecular Weight; D009130:Muscle, Smooth / Q000032:analysis*
D000596:Amino Acids; D002148:Calmodulin-Binding Proteins