Troponin-I is one of three subunits that form the troponin complex of the thin filaments of striated muscle.  The troponin complex serves as a calcium-sensitive switch that regulates striated muscle contraction.  Tn-I binds actin and inhibits actomyosin ATPase activity in the abscence of calcium.  Skeletal muscle Tn-I exists in two isoforms, TnI-fast and TnI-slow, expressed respectively in fast and slow-twitch muscle fibers.  The two isoforms are characterized by molecular weights of ~21 kDa (fast) and ~22 kDa (slow).  The ratios of slow and fast isoforms vary with muscle source and species.  Skeletal muscle Tn-I offered by TriChem Resources is likely a mixture of slow and fast isoforms.  It is purified by ion-exchange chromatography in conjunction with calcium dependent affinity chromatography on Troponin-C agarose.

HAZARD TESTING & WARNINGS:

N/A

Use Statement: For use in Research or Remanufacture of non-injectable products  not subject to license under PHS Act Section 351 only.