Nucleotide dependent intrinsic fluorescence changes of W29 and W36 in smooth muscle myosin.

ABSTRACT: The intrinsic fluorescence of smooth muscle myosin is sensitive to both nucleotide binding and hydrolysis. We have examined this relationship by making MDE mutants containing a single tryptophan residue at each of the seven positions found in the wild-type molecule. Previously, we have demonstrated that a conserved tryptophan residue (W512) is a major contributor to nucleotide-dependent changes of intrinsic fluorescence in smooth muscle myosin. In this study, an MDE containing all the endogenous tryptophans except W512 (W512 KO-MDE) decreases in intrinsic fluorescence upon nucleotide binding, demonstrating that the intrinsic fluorescence enhancement of smooth muscle myosin is not solely due to W512. Candidates for the observed quench of intrinsic fluorescence in W512 KO-MDE include W29 and

SUBMITTER: van Duffelen M 

PROVIDER: S-EPMC1304581 | biostudies-literature | 2004 Sep

REPOSITORIES: biostudies-literature