Interplay of actin, ADP and Mg²⁺ interactions with striated muscle myosin: Implications of their roles in ATPase.

ABSTRACT: The effects of Mg²⁺ on the interaction between ADP, a product of the ATPase reaction, and striated muscle myosin-subfragment 1 (S1) were investigated with both functional and spectroscopic methods. Mg²⁺ inhibited striated muscle myosin ATPase in the presence of F-actin. Significant effects of Mg²⁺ were observed in both rate constants of NOE build-up and maximal intensities in WaterLOGSY NMR experiments as F-actin concentration increased. In the absence of F-actin, myosin S1 with Mg²⁺ bound to a fluorescent ADP analog about five-times tighter than without Mg²⁺. In the presence of F-actin, the affinity of myosin S1 toward the ADP analog significantly decreased both with and without Mg²⁺. The equilibrium titration of myosin-S1

SUBMITTER: Kobayashi M 

PROVIDER: S-EPMC7201126 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature