Adiabatic compressibility of myosin subfragment-1 and heavy meromyosin with or without nucleotide.

AUTOR(ES)

Tamura, Y

RESUMO

The partial specific adiabatic compressibilities of myosin subfragment-1 (S1) and heavy meromyosin (HMM) of skeletal muscle in solution were determined by measuring the density and the sound velocity of the solution. The partial specific volumes of S1 and HMM were 0.713 and 0.711 cm3/g, respectively. The partial specific adiabatic compressibilities of S1 and HMM were 4.2 x 10(-12) and 2.9 x 10(-12) cm2/dyn, respectively. These values are in the same range as the most of globular proteins so far studied. The result indicates that the flexibility of S1 region almost equals to that of HMM. After binding to ADP.orthovanadate, S1 and HMM became softer than their complexes with ADP. The bulk moduli of S1 and HMM were of the order of (4-6) x 10(10) dyn/cm2, which are very comparable with the bulk modulus of muscle fiber.

Documentos Relacionados

• Transient kinetics of the interaction of actin with myosin subfragment-1 in the absence of nucleotide.
• Polarization of fluorescently labeled myosin subfragment-1 fully or partially decorating muscle fibers and myofibrils.
• Flexibility of myosin rod, light meromyosin, and myosin subfragment-2 in solution.
• Cooperative binding of myosin subfragment-1 to the actin-troponin-tropomyosin complex.
• The radius of gyration of native and reductively methylated myosin subfragment-1 from neutron scattering.