Rate constants and equilibrium constants for binding of actin to the 1:1 gelsolin-actin complex
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چکیده
منابع مشابه
Rate constants for the reactions of ATP- and ADP-actin with the ends of actin filaments
I measured the rate of elongation at the barbed and pointed ends of actin filaments by electron microscopy with Limulus sperm acrosomal processes as nuclei. With improvements in the mechanics of the assay, it was possible to measure growth rates from 0.05 to 280 s-1. At 22 degrees C in 1 mM MgCl2, 10 mM imidazole (pH 7), 0.2 mM ATP with 1 mM EGTA or 50 microM CaCl2 or with EGTA and 50 mM KCl, t...
متن کاملPrediction and Dissection of Widely-Varying Association Rate Constants of Actin-Binding Proteins
Actin is an abundant protein that constitutes a main component of the eukaryotic cytoskeleton. Its polymerization and depolymerization are regulated by a variety of actin-binding proteins. Their functions range from nucleation of actin polymerization to sequestering G-actin in 1∶1 complexes. The kinetics of forming these complexes, with rate constants varying at least three orders of magnitude,...
متن کاملGelsolin has three actin-binding sites
Gelsolin, a Ca2+-modulated actin filament-capping and -severing protein, complexes with two actin monomers. Studies designed to localize binding sites on proteolytic fragments identify three distinct actin-binding peptides. 14NT, a 14-kD fragment that contains the NH2 terminal, will depolymerize F-actin. This peptide forms a 1:1 complex with G-actin which blocks the exchange of etheno-ATP from ...
متن کاملKinetic analysis of F-actin depolymerization in the presence of platelet gelsolin and gelsolin-actin complexes
Platelet gelsolin (G), a 90,000-mol-wt protein, binds tightly to actin (A) and calcium at low ionic strength to form a 1:2:2 complex, GA2Ca2 (Bryan, J., and M. Kurth, 1984, J. Biol. Chem. 259:7480-7487). Chromatography of actin and gelsolin mixtures in EGTA-containing solutions isolates a stable binary complex, GA1Ca1 (Kurth, M., and J. Bryan, 1984, J. Biol. Chem. 259:7473-7479). The effects of...
متن کاملDirect measurement of actin polymerization rate constants by electron microscopy of actin filaments nucleated by isolated microvillus cores
We used actin filament bundles isolated from intestinal brush-border microvilli to nucleate the polymerization of pure muscle actin monomers into filaments. Growth rates were determined by electron microscopy by measuring the change in the length of the filaments as a function of time. The linear dependence of the growth rates on the actin monomer concentration provided the rate constants for m...
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ژورنال
عنوان ژورنال: European Journal of Biochemistry
سال: 1991
ISSN: 0014-2956,1432-1033
DOI: 10.1111/j.1432-1033.1991.tb16480.x