The alpha 2 beta 1 integrin binds to the CB4 peptide of the alpha 2(I) collagen chain.
The adhesion of platelets and other cells to type I collagen is mediated by the alpha 2 beta 1 integrin. A binding site for the alpha 2 beta 1 integrin within the alpha 1(I) collagen chain has previously been localized to the cyanogen bromide fragment alpha 1(I)-CB3. We noe show by use of inhibitory monoclonal antibodies against the alpha 2 beta 1 integrin, that platelets also adhere to purified alpha 2(I) collagen chains by a mechanism mediated by the alpha 2 beta 1 integrin. Moreover, following isolation of cyanogen bromide fragments of the alpha 2(I) collagen chain by HPLC, we demonstrate that alpha 2 beta 1 integrin-mediated adhesion is restricted to the CB4 fragment of the alpha 2(I) collagen polypeptide. These findings indicate the presence of at least two spatially distinct binding sites for the alpha 2 beta 1 integrin on the native type I collagen triple helix.
Staatz
W D
WD
Department of Pathology, Washington University School of Medicine, Saint Louis, MO 63110, USA.
Walsh
J J
JJ
Santoro
S A
SA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D001665:Binding Sites; D002417:Cattle; D002448:Cell Adhesion; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000378:metabolism*; D016023:Integrins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D011485:Protein Binding; D038981:Receptors, Collagen
D000911:Antibodies, Monoclonal; D016023:Integrins; D010446:Peptide Fragments; D038981:Receptors, Collagen; D003094:Collagen