title: Individual states in the cycle of muscle contraction.
abstract: By using appropriate analogs of ATP, isometrically-held glycerol-extracted psoas fibers from rabbits are forced successively into states corresponding to molecular species in the contractile cycle. In each state measurements are made of P[unk], a fluorescence polarization parameter thought to relate to attitude of S-1 moieties of the myosin molecules. Also, the value of P[unk] is measured during active tension development. It is suggested that this value is a time-average of the P[unk] as S-1 moieties move through the various states of the cycle. Proposals are made concerning the sequence of states in the cycle.
mesh_terms: D000199:Actins; D000227:Adenine Nucleotides / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D011756:Diphosphates / Q000494:pharmacology; D004220:Disulfides / Q000494:pharmacology; D007292:Inosine Nucleotides / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology; D008433:Mathematics; D008954:Models, Biological; D009119:Muscle Contraction; D009132:Muscles / Q000187:drug effects*; D009218:Myosins; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D013438:Sulfhydryl Compounds / Q000494:pharmacology
chemical_list: D000199:Actins; D000227:Adenine Nucleotides; D011756:Diphosphates; D004220:Disulfides; D007292:Inosine Nucleotides; D013438:Sulfhydryl Compounds; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D009218:Myosins; D008274:Magnesium; D002118:Calcium