Comparative calcium binding and conformational studies of turkey and rabbit skeletal troponin C.
Troponin C from turkey skeletal muscle has been compared with its chicken counterpart in terms of amino acid composition and fragmentation patterns and with rabbit TN-C by Ca2+ binding and conformational response to Ca2+ as monitored by CD and fluorescence. Cyanogen bromide and tryptic digestion mixtures of chicken and turkey TN-C have been separated by reversed-phase HPLC. The similarity of the elution profiles, along with the almost identical amino acid compositional data, suggest that the sequences are essentially equivalent. Both turkey and rabbit TN-C bound 2 mol Ca2+/mol protein at pH 5.3, while at pH 6.8, this figure was raised to 4 mol/mol protein. Circular dichroism and fluorescence measurements indicated that the conformations of the two proteins responded in a very similar manner to the presence of Ca2+.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010446:Peptide Fragments / Q000032:analysis; D011487:Protein Conformation; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D014336:Troponin / Q000378:metabolism*; D019209:Troponin C; D014422:Turkeys
D000596:Amino Acids; D010446:Peptide Fragments; D014336:Troponin; D019209:Troponin C; D002118:Calcium