title: Structural studies of rigor bovine myofibrils using fluorescence microscopy. I. Procedures for purification and modification of bovine muscle proteins for use in fluorescence microscopy.
abstract: The myofibril is a fully competent fragment of the contractile apparatus of muscle, and its structure can be investigated with fluorescent-protein probes. Several purification and chemical modification techniques were developed for the synthesis of fluorescent myosin subfragment-1 (S1), actin and alphaactinin to be used as fluorescent probes of myofibril structure. Myosin was isolated from both rectus abdominis (RA) and cutaneus trunci (CT) and subjected to chymotryptic digestion to give S1 and myosin rod. Analysis of the time course of digestion by SDS-PAGE showed that S1 from RA myosin contained at least three heavy chain fragments while myosin from CT had essentially one. The S1 obtained from CT myosin was enzymatically characterized and used for fluorescent conjugation. Methods were adapted to conjugate thiol-specific fluorophores to actin, alpha-actinin and S1. These fluorescent probes may be useful for structural studies on the isolated myofibril and on muscle in relation to its properties as a food.
authors: Meat Science and Muscle Biology Laboratory, University of Wisconsin-Madison, Madison WI 53706, USA.
authors: D R
authors: DR
authors: Swartz
authors: M L
authors: ML
authors: Greaser
authors: B
authors: B
authors: Bruce Marsh