Amino Acid Sequence of Calmodulin from Wheat Germ

Abstract

The complete amino acid sequence of calmodulin from wheat germ was determined by isolating and sequencing the cyanogen bromide and tryptic peptides. The protein consisted of 149 amino acid residues and its amino(N)-terminus was blocked with an acetyl group. Wheat germ calmodulin lacked tryptophan and contained 1 mol each of histidine, tyrosine, cysteine, and N'-trimethyllysine residues per mol of the protein. A comparison of its amino acid sequence with that of bovine brain calmodulin indicated that there were eleven amino acid subsitutions other than amide assignments, two insertions and one deletion of amino acid residues in wheat germ calmodulin.