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Tropomyosin is in a reduced state in rabbit psoas muscle

  • Sherwin S. Lehrer
  • Socheata Ly
  • Franklin Fuchs
Rapid Communication

Summary

Tropomyosin (Tm) purified from skeletal and cardiac muscle often contains disulfide bonds due to oxidation of cysteine groups that are in close proximity in the coiled-coil structure. Are these disulfide crosslinks present in the muscle or produced by oxidation during preparation? To answer this question we reacted one part of freshly dissected rabbit psoas muscle fibers, which was permeabilized with Triton X-100, with N-ethyl maleimide (NEM) to block cysteine groups and another part with 5,5′-dithiobis(2-nitro benzoate) (DTNB) to facilitate disulfide bond formation by interchain sulfhydryl-disulfide exchange. We found, by high resolution gradient SDS polyacrylamide gels, that the NEM-treated muscle was only composed of uncrosslinked Tm and the DTNB treated muscle was composed of disulfide-crosslinked Tm. This work indicates that Tm exists in a reduced state in rabbit psoas muscle.

Keywords

Tropomyosin Muscle Reduced Crosslinked 

Notes

Acknowledgments

We appreciate the critical reading of the manuscript by Dr. Zenon Grabarek and support from National Institutes of Health (HL91162).

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Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Sherwin S. Lehrer
    • 1
    • 2
  • Socheata Ly
    • 1
  • Franklin Fuchs
    • 1
  1. 1.Cardiovascular Program, Boston Biomedical Research InstituteWatertownUSA
  2. 2.Department of NeurologyHarvard Medical SchoolBostonUSA

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