GFP-tagged regulatory light chain monitors single myosin lever-arm orientation in a muscle fiber.

ABSTRACT: Myosin is the molecular motor in muscle-binding actin and executing a power stroke by rotating its lever arm through an angle of approximately 70 degrees to translate actin against resistive force. A green fluorescent protein (GFP)-tagged human cardiac myosin regulatory light chain (HCRLC) was constructed to study in situ lever arm orientation one molecule at a time by polarized fluorescence emitted from the GFP probe. The recombinant protein physically and functionally replaced the native RLC on myosin lever arms in the thick filaments of permeabilized skeletal muscle fibers. Detecting single molecules in fibers where myosin concentration reaches 300 microM is accomplished using total internal reflection fluorescence microscopy. With total internal reflection fluorescence, evanescent fiel

SUBMITTER: Burghardt TP 

PROVIDER: S-EPMC1959555 | biostudies-literature | 2007 Sep

REPOSITORIES: biostudies-literature