Primary Structure of Parvalbumin from Rat Skeletal Muscle

Abstract
The primary structure of parvalbumin from rat skeletal muscle has been determined principally by automated sequencing of tryptic peptides using 4‐N,N‐dimethylaminoazobenzene 4′‐isothiocyanate as the Edman reagent on a solid‐phase sequencer. Remaining positions and most peptide overlaps were identified by analysis of peptides arising from CNBr, chymotryptic and Staphylococcus aureus protease cleavages and through digestions with carboxypeptidases A, B and Y. Reverse‐phase high‐performance liquid chromatography on C‐18 supports was employed for all peptide separations. Structural homology between rat and rabbit parvalbumins helped to confirm the alignments of the tryptic peptides T4‐T3, T2‐T6 and to define the position of the Lys triplet (36–38). A comparison of the two mammalian proteins revealed 14 amino acid differences, which are all located on the surface of the molecule. A prediction of the secondary structure has been made and found to be very similar for the rat and rabbit proteins with the exception of the sequence region 72–78, located between the Ca2+, Mg2+‐binding CD and EF domains.