Tm. Chiang et al., CLONING, CHARACTERIZATION, AND FUNCTIONAL-STUDIES OF A NONINTEGRIN PLATELET RECEPTOR FOR TYPE-I COLLAGEN, The Journal of clinical investigation, 100(3), 1997, pp. 514-521
A cDNA (1.6 kb) encoding a platelet protein receptor that binds type I
collagen has been isolated from a human bone marrow cDNA library by u
sing a degenerate oligonucleotide probe derived from the amino acid se
quence of a CNBr fragment of the purified receptor, Computer search re
vealed that this cDNA represents the coding sequence of a unique prote
in, Using the prokaryotic expression system pKK 223-3-65 cDNA, a 54-kD
recombinant protein was obtained and purified to apparent homogeneity
, In an eukaryotic expression vector (pcDNA3-65 cDNA), a 65-kD protein
was identified that was recognized by monoclonal anti-65 kD antibody
(anti-65m), The recombinant protein binds to type I, but not to type I
II collagen by affinity column chromatography, The binding of the reco
mbinant protein to type I collagen-coated Petri dishes is inhibited by
anti-65m in a dose-dependent manner, The pcDNA3-65 cDNA-transfected n
onadherent T cells express the protein, allowing them to attach to a t
ype I collagen matrix, and are inhibited by anti-65m in a dose-depende
nt manner, Like the receptor protein purified from platelet membranes,
the recombinant protein inhibits type I collagen-induced platelet agg
regation and the adhesion of [C-14]serotonin-labeled platelets to type
I collagen in a dose-dependent manner, The recombinant protein neithe
r binds to type III collagen-coated Petri dishes nor inhibits type III
collagen and ADP-induced platelet aggregation, indicating specificity
for type I collagen.