Preparation and characterization of fluorescent N-(3-pyrene)maleimide adducts of myosin.
N-(3-pyrene)maleimide adducts of myosin (PM-myosin) are fluorescent and possess actin-activated Mg2+ ATPase activity. Addition of ATP to PM-myosin produces a reversible decrease of 10% in fluorescence intensity of the pyrene fluorophore in the presence of actin. Analogues of ATP which are poor substrates for myosin ATPase or which merely dissociate actomyosin produce less decrease in fluorescence of PM-myosin than does ATP. Since fluorescence of acto-PM-myosin is sensitive to environmental changes associated with ATP hydrolysis, and/or with fluorophore-actin interactions. PM-myosin may be a useful analysis of molecular aspects of muscle contraction.
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology; D003597:Cytosine Nucleotides / Q000494:pharmacology; D005453:Fluorescence; D006160:Guanosine Triphosphate / Q000494:pharmacology; D008301:Maleimides; D008623:Mercaptoethanol; D009218:Myosins / Q000378:metabolism*; D011721:Pyrenes; D013050:Spectrometry, Fluorescence
D003597:Cytosine Nucleotides; D008301:Maleimides; D011721:Pyrenes; D008623:Mercaptoethanol; D000244:Adenosine Diphosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; C003944:N-(3-pyrene)maleimide; D000251:Adenosine Triphosphatases; D009218:Myosins