Unlike animal skeletal muscle, myosin light chain kinase and phosphatase activities appear similar in human fast and slow muscle fibres.
Questions translation of rodent muscle data to humans; leaves open functional impact of P-light chain phosphorylation on exercise performance.
The phosphate content of the fast (LC2F) and two slow (LC2S and LC2S1) phosphorylatable light chains (P-light chains) in myosin isolated from biopsy samples of rested human vastus lateralis muscle averaged 0.21, 0.28 and 0.25 mol of phosphate per mol of P-light chain, respectively. Following a 10 s maximal contraction, phosphate content was increased by almost 2-fold in the fast and two slow P-light chains. After prolonged, moderate cycling activity phosphate content was only slightly increased in the three P-light chains. These data suggest that, unlike animal skeletal muscle, myosin light chain kinase and phosphatase activities are similar in human fast and slow muscle fibres.
No takes yet. Share an insight, caveat, or question.
Houston et al. (1987) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: