TY - JOUR
T1 - Evidence that a 27-residue sequence is the actin-binding site of ABP-120
AU - Bresnick, Anne R.
AU - Janmey, Paul A.
AU - Condeelis, John
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1991
Y1 - 1991
N2 - Proteolysis experiments of ABP-120 from Dictyostelium discoideum have previously demonstrated that removal of residues 89-115 from a tryptic peptide which retains actin binding activity, abolishes actin binding (Bresnick, A. R., Warren, V., and Condeelis, J. (1990) J. Biol. Chem. 265, 9236-9240). Antibodies made against a synthetic peptide of this 27-amino acid sequence (27-mer) specifically immunoprecipitate native ABP-120 from Dictyostelium high speed supernatants, demonstrating that the 27-mer sequence is on the surface of the molecule as expected for an active rite. ABP-120 is inhibited in its binding to F-actin by Fab′ fragments of the anti-27-mer IgG. Half-maximal inhibition occurs at an approximate molar ratio of 7 Fab′ fragments/ABP-120 monomer. Viscoelastic measurements indicate that ABP-120 forms fewer crosslinks with F-actin in the presence of the 27-mer synthetic peptide than in its absence. In F-actin cosedimentation assays, the binding of ABP-120 to actin is inhibited by the 27-mer synthetic peptide. Furthermore, the 27-mer synthetic peptide cosediments with F-actin, whereas a control hydrophobic peptide and a synthetic peptide of residues 69-88 of ABP-120 do not cosediment with F-actin. These observations suggest a direct involvement of the 27-mer sequence in the actin binding activity of ABP-120.
AB - Proteolysis experiments of ABP-120 from Dictyostelium discoideum have previously demonstrated that removal of residues 89-115 from a tryptic peptide which retains actin binding activity, abolishes actin binding (Bresnick, A. R., Warren, V., and Condeelis, J. (1990) J. Biol. Chem. 265, 9236-9240). Antibodies made against a synthetic peptide of this 27-amino acid sequence (27-mer) specifically immunoprecipitate native ABP-120 from Dictyostelium high speed supernatants, demonstrating that the 27-mer sequence is on the surface of the molecule as expected for an active rite. ABP-120 is inhibited in its binding to F-actin by Fab′ fragments of the anti-27-mer IgG. Half-maximal inhibition occurs at an approximate molar ratio of 7 Fab′ fragments/ABP-120 monomer. Viscoelastic measurements indicate that ABP-120 forms fewer crosslinks with F-actin in the presence of the 27-mer synthetic peptide than in its absence. In F-actin cosedimentation assays, the binding of ABP-120 to actin is inhibited by the 27-mer synthetic peptide. Furthermore, the 27-mer synthetic peptide cosediments with F-actin, whereas a control hydrophobic peptide and a synthetic peptide of residues 69-88 of ABP-120 do not cosediment with F-actin. These observations suggest a direct involvement of the 27-mer sequence in the actin binding activity of ABP-120.
UR - http://www.scopus.com/inward/record.url?scp=0025734201&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025734201&partnerID=8YFLogxK
M3 - Article
C2 - 2071586
AN - SCOPUS:0025734201
SN - 0021-9258
VL - 266
SP - 12989
EP - 12993
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 20
ER -