title: Thermal stability of myosin subfragment-1 decreases upon tryptic digestion in the presence of nucleotides.
abstract: Myosin subfragment-1 (S-1), digested with trypsin in the presence of ATP, rapidly loses its ATPase activity upon mild heat treatment even if ATP or ADP is present. The heat-treated molecule is very sensitive to further tryptic digestion. Undigested S-1 and S-1 digested in the absence of ATP are protected by nucleotides. The loss of the protective effect of nucleotides correlates with the tryptic splitting of the 25 kDa amino-terminal fragment between Arg 23 and Ile 24.
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D002918:Chymotrypsin / Q000378:metabolism; D004355:Drug Stability; D006358:Hot Temperature; D007700:Kinetics; D008970:Molecular Weight; D015879:Myosin Subfragments; D009218:Myosins / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D014357:Trypsin / Q000378:metabolism
chemical_list: D015879:Myosin Subfragments; D010446:Peptide Fragments; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D002918:Chymotrypsin; D014357:Trypsin; D000251:Adenosine Triphosphatases; D009218:Myosins