A synthetic peptide mimics troponin I function in the calcium-dependent regulation of muscle contraction.
A new technique for treating skinned cardiac muscle fibers has been developed in which troponin I is extracted, giving rise to unregulated fibers. The effect of the 12-residue troponin I peptide on these fibers indicates that this region of troponin I is solely responsible for muscle relaxation (inhibition of force). Furthermore, troponin I peptide-troponin C reconstituted fibers are stable through several contraction-relaxation cycles indicating the peptide can switch binding sites between actin and troponin C. The troponin I peptide can substitute for the native protein as part of the calcium-sensitive molecular switch that controls muscle regulation.
Department of Biochemistry, University of Alberta, Edmonton, Canada.
J E
JE
Van Eyk
J D
JD
Strauss
R S
RS
Hodges
J C
JC
Rüegg
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000187:drug effects*; D008969:Molecular Sequence Data; D009132:Muscles / Q000187:drug effects / Q000502:physiology*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000494:pharmacology*; D013552:Swine; D014336:Troponin / Q000302:isolation & purification / Q000494:pharmacology / Q000502:physiology*; D019210:Troponin I; D014638:Vanadates / Q000494:pharmacology
D010446:Peptide Fragments; D014336:Troponin; D019210:Troponin I; D014638:Vanadates; D002118:Calcium