Characterization of the actin polymerization-inhibiting protein from chicken gizzard smooth muscle.
An actin polymerization-inhibiting protein, occurring in crude preparations of vinculin from chicken gizzard, has been found to be heterogeneous. The molecular masses of the polymerization-inhibiting peptides have been reported to range from 20 kDa to 80 kDa [Schröer, E. & Wegner, A (1985) Eur. J. Biochem. 153, 515-520]. In this paper, a 21-kDa peptide was isolated from the bulk of the other peptides by gel chromatography. The 21-kDa peptide was identified as a polymerization-inhibiting peptide by its ability to retard nucleated actin polymerization and to bind polymeric actin when it was blotted onto nitrocellulose. Antiserum raised to the 21-kDa peptide was found to react with almost all peptides of the blotted heterogeneous polymerization-inhibiting protein. The same peptides which reacted with antiserum cosedimented with polymeric actin. The major peptides of the blotted polymerization-inhibiting protein bound polymeric actin. The largest peptide which reacted with antiserum and cosedimented with polymeric actin had a molecular mass of 85 kDa. The results suggest that the preparation of polymerization-inhibiting protein contains mainly polymerization-inhibiting peptides and only some contaminants, and that all the polymerization-inhibiting peptides are proteolytic fragments stemming from a common precursor.
Ruhnau
K
K
Institut für Physiologische Chemie, Ruhr-Universität Bochum, Federal Republic of Germany.
Schröer
E
E
Wegner
A
A
D051339:Actin Depolymerizing Factors; D000199:Actins / Q000378:metabolism; D000818:Animals; D002645:Chickens; D051345:Destrin; D005895:Gizzard, Avian / Q000378:metabolism; D046911:Macromolecular Substances; D008840:Microfilament Proteins / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D009130:Muscle, Smooth / Q000378:metabolism*
D051339:Actin Depolymerizing Factors; D000199:Actins; D051345:Destrin; D046911:Macromolecular Substances; D008840:Microfilament Proteins