Biomaterial Database

Kinetic studies on the association and dissociation of myosin subfragment 1 and actin. 1991

E W Taylor

Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637.

The reactions of pyrene-labeled actin with myosin subfragment 1 (S1) and S1-ligand complexes at low ionic strength are described by the schemes [formula: see text] where M refers to a myosin head; A is actin; L is ligand; the asterisk refers to a high fluorescence state of actin; and K1 and K3 are association constants. K1 is reduced approximately 10-fold for M.ADP or M.pyrophosphate versus M alone. The rate constant of the isomerization step (k2) is 150-200 s-1 for A*M, A*M.ADP, and A*M-pyrophosphate (20 degrees C). The interaction between the ligand the actin binding sites reduces K2 from 2,000 for A*M to 50-100 for A*M.ADP and to approximately unity for A*M-pyrophosphate. The A*M.ADP state is equated with the AM'.ADP state of Sleep and Hutton (Sleep, J., A., and Hutton, R. L. (1980) Biochemistry 19, 1276-1283).

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D008962	Models, Theoretical	Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.	Experimental Model,Experimental Models,Mathematical Model,Model, Experimental,Models (Theoretical),Models, Experimental,Models, Theoretic,Theoretical Study,Mathematical Models,Model (Theoretical),Model, Mathematical,Model, Theoretical,Models, Mathematical,Studies, Theoretical,Study, Theoretical,Theoretical Model,Theoretical Models,Theoretical Studies
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D011756	Diphosphates	Inorganic salts of phosphoric acid that contain two phosphate groups.	Diphosphate,Pyrophosphate Analog,Pyrophosphates,Pyrophosphate Analogs,Analog, Pyrophosphate
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D000199	Actins	Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.	F-Actin,G-Actin,Actin,Isoactin,N-Actin,alpha-Actin,alpha-Isoactin,beta-Actin,gamma-Actin,F Actin,G Actin,N Actin,alpha Actin,alpha Isoactin,beta Actin,gamma Actin
D000244	Adenosine Diphosphate	Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.	ADP,Adenosine Pyrophosphate,Magnesium ADP,MgADP,Adenosine 5'-Pyrophosphate,5'-Pyrophosphate, Adenosine,ADP, Magnesium,Adenosine 5' Pyrophosphate,Diphosphate, Adenosine,Pyrophosphate, Adenosine
D000266	Adenylyl Imidodiphosphate	5'-Adenylic acid, monoanhydride with imidodiphosphoric acid. An analog of ATP, in which the oxygen atom bridging the beta to the gamma phosphate is replaced by a nitrogen atom. It is a potent competitive inhibitor of soluble and membrane-bound mitochondrial ATPase and also inhibits ATP-dependent reactions of oxidative phosphorylation.	Adenyl Imidodiphosphate,gamma-Imino-ATP,AMP-PNP,AMPPNP,ATP(beta,gamma-NH),Adenosine 5'-(beta,gamma-Imino)triphosphate,Adenylimidodiphosphate,Adenylylimidodiphosphate,Mg AMP-PNP,Mg-5'-Adenylylimidodiphosphate,beta,gamma-imido-ATP,gamma-Imido-ATP,AMP-PNP, Mg,Imidodiphosphate, Adenyl,Imidodiphosphate, Adenylyl,Mg 5' Adenylylimidodiphosphate,Mg AMP PNP,beta,gamma imido ATP,gamma Imido ATP,gamma Imino ATP
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia