Disulfide isoforms of recombinant glia maturation factor beta.
Recombinant human glia maturation factor beta (r-hGMF-beta) is a single-chain polypeptide (141 amino acid residues) containing three cysteines, at positions 7, 86 and 95. Nascent r-hGMF-beta exists in the reduced state and has no biological activity. The protein can be activated through oxidative refolding by incubation with a mixture of reduced and oxidized glutathione. Reverse-phase HPLC analysis of the refolded r-hGMF-beta shows the presence of four peaks, corresponding to the reduced form plus three newly generated intrachain disulfide-containing isoforms predicted from the number of cysteine residues. Only one isoform shows biological activity when tested for growth suppression on C6 glioma cells. We infer from the HPLC elution pattern that the active form contains the disulfide bridge Cys86-Cys95.
Department of Neurology, University of Iowa College of Medicine, Iowa City.
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Zaheer
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Lim
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004220:Disulfides / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D020904:Glia Maturation Factor; D005910:Glioma; D006133:Growth Substances; D006801:Humans; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology; D011487:Protein Conformation; D051381:Rats; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000494:pharmacology
D004220:Disulfides; D020904:Glia Maturation Factor; D006133:Growth Substances; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins