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

• Published in: Biophysical journal Vol. 65; no. 5; pp. 1899 - 1905
• Main Authors: Tamura, Y., Suzuki, N., Mihashi, K.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 01.11.1993; Biophysical Society
• Subjects: Adenine Nucleotides - chemistry; Adenine Nucleotides - metabolism; Animals; Biological and medical sciences; Biophysical Phenomena; Biophysics; Cell physiology; Elasticity; Fundamental and applied biological sciences. Psychology; In Vitro Techniques; Isometric Contraction - physiology; Molecular and cellular biology; Muscle contraction; Muscle Contraction - physiology; Myosin Subfragments - chemistry; Myosin Subfragments - metabolism; Protein Binding; Protein Conformation; Rabbits; Solutions; Tensile Strength; Vanadates - metabolism; Proteins; Binding capacity; Meromyosin; Myosin; Contractile protein; Peptide chain; Muscular fiber; Striated muscle; ADP; ATP; Adiabatic compressibility; Induced conformation
• ISSN: 0006-3495; 1542-0086
• DOI: 10.1016/S0006-3495(93)81260-8

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.