Binding domains and epitopes in platelet-derived growth factor.
Trypsin treatment of recombinant PDGF-BB from Escherichia coli leads to the liberation of a small carboxy-terminal fragment and two internal segments without dissociating the molecule. The remaining core of 21 kDa retained a considerable binding affinity of 8.4 nM. By use of various peptide fragments obtained from monomeric recombinant PDGF-B, a receptor binding domain was assigned to one of these internal trypsin-sensitive segments. This segment is enriched in charged residues, suggesting mainly hydrophilic interactions with the receptor. Circular dichroism measurements of recombinant PDGF-BB showed a high content of random structure and only a small percentage (less than 10%) of alpha-helical structures. This structure was very rigid since the addition of 70% trifluoroethanol or 1% SDS did not change the circular dichroism spectrum. On the basis of these results, a tentative structure was generated by computer modeling.
Vogel
S
S
Department of Cytogenetics, GBF--Gesellschaft für Biotechnologische Forschung mbH, Braunschweig, FRG.
Hoppe
J
J
D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D003198:Computer Simulation; D000939:Epitopes / Q000032:analysis*; D007700:Kinetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification; D010982:Platelet-Derived Growth Factor / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011487:Protein Conformation; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017479:Receptors, Platelet-Derived Growth Factor; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism
D000939:Epitopes; D010446:Peptide Fragments; D010982:Platelet-Derived Growth Factor; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D017479:Receptors, Platelet-Derived Growth Factor