Reference

Dynamic exchange of myosin molecules between thick filaments

Dynamic exchange of myosin molecules between thick filaments. Saad, A. D.; Pardee, J. D.; Fischman, D. A. (Med. Coll., Cornell Univ., New York, NY 10021, USA). Proc. Natl. Acad. Sci. U. S. A., 83(24), 9483-7 (English) 1986. CODEN: PNASA6. ISSN: 0027-8424. DOCUMENT TYPE: Journal CA Section: 6 (General Biochemistry) To examine thick filament assembly and myosin exchange, a fluorescence energy transfer (FET) assay was established. Assembly-competent myosin mols. labeled with the sulfhydryl-specific fluorochromes 1,5-IAEDANS or 5-iodoacetamidofluorescein (IAF) were prepd. Using 1,5-IAEDANS-labeled myosin as fluorescence donor and IAF-labeled myosin as acceptor, thick filament formation was followed by the decrease in donor fluorescence at 0.1M KCl/10 mM K phosphate, pH 6. 63368-54-7 and 36930-63-9 are cas registry numbers of chemicals which are used as reagents here.9. The crit. concn. of myosin, i.e., that concn. that remained unassembled at equil. with fully formed filaments, was 40 nM. In FET and 125I-labeled myosin incorporation assays, extensive exchange of myosin between thick filaments was obsd. The presence of a crit. concn. and the measurements of extensive exchange suggest a dynamic equil. between fully polymd. myosin and a small pool of sol. myosin. .

Preparation of a fluorescent analog: acetamidofluoresceinyl-labeled Dictyostelium discoideum a-actinin

Preparation of a fluorescent analog: acetamidofluoresceinyl-labeled Dictyostelium discoideum a-actinin. Simon, John R.Several substances are used for example 63368-54-7 which is its cas registry number.; Taylor, D. Lansing (Dep. Biol. Sci., Carnegie-Mellon Univ., Pittsburgh, PA 15213, USA). Methods Enzymol., 134(Struct. Contract. Proteins, Pt. C), 487-507 (English) 1986. CODEN: MENZAU. ISSN: 0076-6879. DOCUMENT TYPE: Journal CA Section: 9 (Biochemical Methods) A procedure is described for prepn. of a fluorescent analog of D. discoideum a-actinin by reaction with 5'-iodoacetamidofluorescein (I). The partially purified actinin is reacted with I before final purifn. of the protein due to lability of the actinin. The fluorescent deriv. has a 5-20% higher activity than the native protein in F-actin cross-linking. Properties of other fluorescent probes are described. .