The study identifies the specific isoenzyme and light-chain composition of human type 1 and type 2 skeletal muscle fibers, explaining literature discrepancies.
May aid preclinical fiber-type research; leaves open human validation and clinical translation.
Human myosin from different skeletal muscles was analysed in a non-denaturing gel system, and the isoenzyme composition correlated with the histochemical composition of the muscle. Two components (SM1 and SM2) were associated with type 1 (slow-twitch) fibres, and three (FM1, FM2 and FM3) with type 2 (fast-twitch) fibres. Light-chain analysis was performed in sodium dodecyl sulphate/polyacrylamide gels. There are three light chains (LCs1a, LCS1b and LCs2) in type 1 fibres, and three (LCf1, LCf2 and LCf3) in type 2 fibres. LCf1 and LCs1b co-migrate in sodium dodecyl sulphate gels. The ratio of LCf3/LCf2 is correlated with the distribution of the individual fast isoenzymes. These results explain apparent discrepancies in the literature concerning the light-chain distribution of human myosin.
No takes yet. Share an insight, caveat, or question.
Fitzsimons et al. (1981) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: