| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2000: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
Arg-Gly-Asp-Xaa (RGDX) sequence is a cell-adhesion motif present in several matrixassociated adhesive glycoproteins including fibronectin, vitronectin, and fibrinogen. The RGDX sequence is recognized by several integrins, including the platelet, fibroblast cell, and so on. It has been demonstrated that soluble peptides containing the RGD sequence compete with RGDcontaining insoluble matrix proteins for binding to their respective integrins, and thus prevent cellmatrix adhesion. However, the affinity of the short synthetic peptides to their corresponding integrins is lower than that of proteins. In this work, we designed and synthesized Arg-Gly-AspSer (RGDS) mimetic peptides for the purpose of improving the cell attachment activity of RGDS oligopeptide, and their cell-attachment activities were assayed by L929 fibroblast cell toward peptide-immobilized polymeric materials and platelet aggregation inhibition method. Then we discussed on the structure and activity relationship of RGDS mim
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etic peptides.
RGDS and its mimetic peptides, and RGDS containing β -sheet model peptides were synthesized using liquid ancl solid phase procedures. All peptides were characterized by NMR, MALDI-TOF MS, amino acid analysis, and elemental analysis. Cell-attachment activities of these peptides were examined by cell- attachment test using L929 fibroblast cell toward peptide-immobilized PVA film.
Number of L929 cells attaching to RGDS mimetic peptide-immobilized PVA films at incubation times of 1, 3, 6 and 24 hr. The cell-attachment activity of Har-Gly-Asp-Ser (hRGDS) and Orn-Gly-Asp-Ser (OrGDS) was the same as that of RGDS. However, the cell attachment activity of Arg-Nip-Asp-Ser (RNiDS) was higher than that of RGDS from the initial stage, and cell attachment activity of RNiDS was about eight times as high as that of RGDS after incubation for 24hr. The hRGDS and OrGDS peptides present the same CD spectra as that ofRGDS. The spectral patterns suggested that these peptides possess a type I-β bend. However, RNiDS takes a typical type II-β bend. RNiDS peptide takes the different type of turn structure in comparison with the other RGDS mimetic peptides. It seems that RNiDS forms the optimum conformation for binding to the integrin receptor. It is necessary that for the active expression, the RGDS mimetic peptides take the optimum conformation in the PVA film surface. The nipecotic acid residue of RNiDS appears to contain an important structural motif that contributed to the observed cell-attachment activity. Less
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