Characterizing the concentration and load dependence of phosphate binding to rabbit fast skeletal actomyosin.

ABSTRACT: Intensely contracting fast skeletal muscle rapidly loses the ability to generate force, due in part to the accumulation of phosphate (P_i) inhibiting myosin's force-generating capacity, in a process that is strain dependent. Crucial aspects of the mechanism underlying this inhibition remain unclear. Therefore, we directly determined the effects of increasing [P_i] on rabbit psoas muscle myosin's ability to generate force against progressively higher resistive loads in a laser trap assay, with the requisite spatial and temporal resolution to discern the mechanism of inhibition. Myosin's force-generating capacity decreased with increasing [P_i], an effect that became more pronounced at higher resistive loads. The decrease in force resulted from myosin's accelera

SUBMITTER: Marang CP 

PROVIDER: S-EPMC12107134 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature