This study was aimed to further investigate the function of platelet collagen receptor-glycoprotein VI and to screen its specific inhibitor. The extracellular domain of platelet glycoprotein VI (GPVI) in E. coli was expressed by recombinant technology, the extracellular domain cDNA of GPVI was amplified from pBluescript KS(-)-GPVI plasmid by PCR. Proved by sequencing, the expression vector pET-20b(+)-GPVI was constructed, which was then transformed into E. coli (BL21(DE3)pLysS) and induced by IPTG. The recombinant GPVI was purified on Ni-NTA resin column and renatured in PBS containing GSH and GSSG. The anti-penta His McAb and anti-GPVI polyclonal antibody were used to identify the recombinant GPVI in Western blotting. Collagen binding test was conducted to investigate the biological activity of recombinant GPVI. The results showed that the recombinant GPVI was expressed in E. coli and successfully purified, which was confirmed to be similar to the native GPVI in Western blotting. The recombinant GPVI can bind the type I collagen in dose-dependent manner. In conclusion, the recombinant GPVI can be achieved in E. coli and restore its native characteristics after renaturation.
Blood Platelets ; metabolism ; Blotting, Western ; Escherichia coli ; genetics ; Humans ; Integrin alpha2beta1 ; Platelet Membrane Glycoproteins ; biosynthesis ; genetics ; Protein Binding ; Receptors, Collagen ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; isolation & purification

CD63, which belongs to the tetraspanin membrane proteins, has been proposed to play an important role in inhibiting melanoma metastasis. To determine whether reduction of CD63 expression, which frequently occurs in the malignant progression of human melanoma, is responsible for metastasis promotion, we transfected the antisense CD63 cDNA into MelJuso melanoma cells having endogenous CD63 expression. The antisense CD63 transfectant clones showing decreased CD63 expression displayed increased cell motility, matrix-degrading activity, and invasiveness in vitro when compared with the control transfectant cells. The antisense CD63 cDNA-transfected cells also exhibited altered adhesiveness to extracellular matrix. The results suggest that reduced CD63 expression contributes to the invasive and metastatic ability of human melanoma cells.
Antigens, CD/biosynthesis/*genetics ; Gene Expression Regulation, Neoplastic ; Human ; Melanoma/*genetics/metabolism ; Neoplasm Invasiveness/*genetics ; Platelet Membrane Glycoproteins/biosynthesis/*genetics ; Reverse Transcriptase Polymerase Chain Reaction

Animals ; Cell Division ; drug effects ; Cells, Cultured ; Fas Ligand Protein ; Interleukin-10 ; pharmacology ; Liver ; immunology ; metabolism ; Male ; Membrane Glycoproteins ; biosynthesis ; genetics ; Platelet-Derived Growth Factor ; pharmacology ; Rats ; Rats, Wistar ; fas Receptor ; biosynthesis ; genetics