Fluorescence energy transfer between subfragment-1 and actin points in the rigor complex of actosubfragment-1.
The fast-reacting thiol (SH1) of myosin subfragment-1 (S-1) was covalently and specifically labeled with (iodoacetamido)fluorescein (IAF), while Cys-373 of actin was also covalently and preferentially labeled with N-(iodoacetyl)-N'-(1-sulfo-5-naphthyl)ethylenediamine (1,5-IAEDANS). The method of fluorescence energy transfer was used to examine the spatial proximity between the two sites, i.e., SH1 and Cys-373, in the rigor complex of acto-S-1. Approximately 30% fluorescence energy transfer was observed from the 1,5-IAEDANS on actin as a donor to the IAF on S-1 as an acceptor in their rigor complex; under certain assumptions this corresponds to a distance of ca. 6.0 nm.
D000199:Actins / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D004735:Energy Transfer; D007700:Kinetics; D008433:Mathematics; D009132:Muscles / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis; D011817:Rabbits; D013050:Spectrometry, Fluorescence; D014357:Trypsin
D000199:Actins; D000596:Amino Acids; D010446:Peptide Fragments; D014357:Trypsin; D000251:Adenosine Triphosphatases; D000252:Calcium-Transporting ATPases