Video 1.
SPOCs in detergent-skinned cardiomyocytes from a homozygous Spy-C mouse. Three activations are shown for the same permeabilized homozygous Spy-C myocyte preparation in a submaximal pCa solution near the pCa50 for force development. Left: Myocyte preparation is shown actively contracting at steady-state force before treatment with TEVp (control). Middle: The same myocyte preparation is shown contracting at steady-state force after treatment with TEVp to remove domains C0–C7 of cMyBP-C. Note the vigorous and continuous oscillatory wave behavior (SPOCs) after removal of C0–C7. Right: The same myocyte preparation is shown contracting at steady-state force after ligation with recombinant (r) C0C7-sc. Note that force oscillations (SPOCs) are completely damped after C0–C7 replacement with rC0-C7-sc.