Growth factor from human milk: purification and characterization.
A protein (HPLC-P-1) purified from human milk induced the proliferation of IMR-90 cells (human fetal lung fibroblast cells, diploid) and was named milk growth factor (MGF). The human MGF (HPLC-P-1 fraction) showed a molecular size of 8 kDa on SDS-polyacrylamide gel electrophoresis (PAGE). The band on SDS-PAGE was also detected by Western blotting with anti-human MGF. However, this MGF showed two bands (MGF-S1 and MGF-S2) on 9.8% polyacrylamide native PAGE. The amino acid compositions of MGF-S1 and MGF-S2 were almost the same, but completely different from those of EGF, IGF-1 and TGF beta. The amino acid sequence of NH2-terminal of MGF was T.K.F.E.L.Y.Q.L.L.K.D.I. Neither EGF nor IGF-1 was detectable in the human MGF fraction by RIA. The effects of human MGF on IMR 90 cells (increases in cell number, incorporation of 3H-thymidine and DNA amount) were dose dependent. The activating effect on incorporation of 3H-thymidine (methyl-3H) was suppressed by anti-human MGF antibody in a dose-dependent manner. All these results indicate that MGF purified from human milk activates the growth of IMR-90 cells.
Department of Biochemistry, Nippon Medical School, Tokyo, Japan.
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Y
Kanda
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Yamamoto
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Abe
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002452:Cell Count / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004247:DNA / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D004815:Epidermal Growth Factor / Q000032:analysis; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D006133:Growth Substances / Q000032:analysis / Q000302:isolation & purification* / Q000494:pharmacology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007700:Kinetics; D008168:Lung / Q000166:cytology / Q000187:drug effects; D008895:Milk, Human / Q000737:chemistry*; D008969:Molecular Sequence Data; D011817:Rabbits; D012967:Sodium Dodecyl Sulfate; D013268:Stimulation, Chemical; D013936:Thymidine / Q000378:metabolism; D016212:Transforming Growth Factor beta; D014316:Tritium
D000596:Amino Acids; D000906:Antibodies; D006133:Growth Substances; D016212:Transforming Growth Factor beta; D014316:Tritium; D012967:Sodium Dodecyl Sulfate; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I; D004247:DNA; D013936:Thymidine