| Research Abstract |
In this study, biologically active growth modulators in human gastric juice and antisense homology box theory (Nature Med 1 : 894-901,1995) for making inhibitor of growth factor action were evaluated. Mitogenic activity was evaluated by the incorporation of [^3H] thymidine into 3T3 fibroblasts. A negative correlation was observed between pH and mitogenic activity in gastric juice. The concentrations of epidermal growth factor (EGF), transforming growth factor-a &-b1 (TGF-a & b1), platelet-derived growth factor (PDGF), and basic fibroblast growth factor (bFGF) in gastric juice did not explain these changes in mitogenic activity. Gel filtration identified growth stimulating activity due to small molecule mitogens (less than 13 kDa), and growth inhibitory activity in only neutral samples due to a macromolecular substance (lager than 240 kDa) susceptible to trypsin digestion, heat-and acid-treatments. EGF receptor molecule was analyzed by our software on IBM computer to determine the number and distribution of intramoecular regions having sense-antisense relationships in randomly selected sets of protein. According to this analysis, following peptide was synthesized ; PSGTARTKLLL,LAALCAAGGALEEKKV,LYENTYALAVLSNYG,DSLSINA,NGIGIGE,DPRELEILKTVKEITGFLLI,LHILPVAFK-GDSFTRTPPL,VERIPLENLQIIRGNALY,RGRTKQHGQFSLAVVGLN,HNQSAAGSTGPRESDAL,LVWKFADANNVAHLSHA,QYYLESIRV-LERVKYIR,YVVTDHGSAVRASG,LRSLKEISDGDVI,QITKLLDG-TSIYY.Biological activity of these peptide was evaluated by measuring incorporation of [^3H] thymidine into RGM1 (gastric epithelium), and intracellular concentration of Ca^<++> of rat hepatocyte. DPRELEILKTVKEITGFLLI enhanced action of EGF,but others did not show significant actions, which may indicate these peptide need the flanking regions for increasing biological activity.
|
