Anomalous binding of MgADP to myosin of skeletal muscle.
Binding of adenosine diphosphate to skeletal muscle myosin was studied using a range of concentrations from 0 to 2 mM. Up to 0.2 mM adenosine diphosphate two equivalent and independent nucleotide binding sites were detected, characterized by the single association constant of 5 x 10(4)M(-1). At greater adenosine diphosphate concentrations a decreasing binding capacity was noticed, bound nucleotide being essentially approximately 0.1 mol/mol at a 1-2mM adenosine diphosphate concentration. We tentatively propose that nucleotides act indirectly on myosin by promoting the perturbation of the solvent, which is supported by the fact that polyphosphates are known powerful kosmotropes.
Grazi
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Dipartimento di Biochimica e Biologia Molecolare, Università di Ferrara, Italy.
Cintio
O
O
Magri
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E
Trombetta
G
G
D000244:Adenosine Diphosphate / Q000378:metabolism*; D000818:Animals; D003956:Dialysis; D018482:Muscle, Skeletal / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000378:metabolism; D011485:Protein Binding; D011817:Rabbits; D014867:Water
D014867:Water; D011092:Polyethylene Glycols; D000244:Adenosine Diphosphate; D009218:Myosins