Amino acid sequences of the cardiac L‐2A, L‐2B and gizzard 17 000‐M_r light chains of chicken muscle myosin

Two forms of the P light chain of myosin in rabbit and bovine hearts

“…Primary sequence differences between the 2 peptides were not readily apparent from amino acid analysis of the 2 forms of the bovine ventricular P light chain isolated by isoelectric focusing (table 1). In this respect the analyses are very similar to those in [20] for the 2 forms of P light chains of myosin from the chicken ventricle. The differences in the alanine and histidine contents of the 2 forms present in the bovine ventricle are possibly significant.…”

“…We have demonstrated that the P light chain exists in two forms, P1 and P2, in ventricular muscle from several species [ 19]. This observation is supported by the recent report of two P light chains of different amino acid sequence in chicken ventricular myosin [20].…”

“…Taken with the results in [20] it suggests that polymorphism of the P light chain is a general property of myosin from the vertebrate heart, although the adult rat and adult mouse hearts are exceptions to this rule [19]. Both forms of P light chain can be phosphorylated in situ, but their roles are as yet uncertain.…”

“…After 60 rain digestion of light chain P2, small amounts of an acidic peptide a From sequence data in [20] Analysis performed in duplicate on 2 preparations as in [ 31 ]; n.d., not determined appeared, but by this time more acidic peptides had appeared in the digest of light chain P1. These studies suggest that differences exist in the structures of the 2 light chains which result in light chain P1 being more susceptible to digestion with thermolysin in the presence of 4 M urea.…”

Isolation of cardiac myosin light‐chain isotypes by chromatofocusing

“…Although VLC-1 differs from FLC-1 and ALC-1 in apparent molecular mass when electrophoresed using the conditions of Laemmli [20], no other evidence is available to suggest that they differ significantly in molecular mass (see Discussion). Results were therefore normalised for an M , of 21600 which is that calculated from the known primary sequence of chicken cardiac light chain 1 [30]. All of the human light chains analysed had broadly comparable amino acid compositions which were also similar to those previously published for the bovine cardiac light chain 1 types [31].…”