The mechanism for mechanochemical energy transduction in actin-myosin interaction revealed by in vitro motility assay with ATP analogues.
We investigated in vitro motility of F-actin on heavy meromyosin (HMM) and nucleotide triphosphatase activity of acto-HMM by using ATP analogues of various nucleotide triphosphates (NTPs) and enzymatically cleaved actins. The sliding velocity did not correlate with the actin activated HMM-NTPase activity, but correlated strongly with the reciprocal of NTPase activity of HMM itself, i.e., the cycle time of HMM NTPase. This indicated that with ATP the complex of myosin with the product, M.ADP.Pi, at the long lived intermediate state of the rate limiting step would play a key role for efficient mechanochemical energy transduction during actin-myosin interaction.
Higashi-Fujime
S
S
Department of Molecular Biology, Faculty of Science, Nagoya University, Japan.
Hozumi
T
T
D000199:Actins / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives*; D000818:Animals; D004734:Energy Metabolism; D006868:Hydrolysis; D015879:Myosin Subfragments / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D011485:Protein Binding; D011817:Rabbits
D000199:Actins; D015879:Myosin Subfragments; D000255:Adenosine Triphosphate; D010744:Phosphoric Monoester Hydrolases