Purification and partial characterization of a hepatocyte antiproliferative glycopeptide

✍ Scribed by Geneviève Auger; Didier Blanot; Jean Van Heijenoort; Claude Nadal; Marie-Françoise Gournay; Jean-Jacques Winchenne; Georges A. Boffa; Patrick Lambin; Pierrette Maes; André Tartar

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 783 KB
• Volume: 40
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240400405

✦ Synopsis

A low molecular weight compound, which inhibits the GI-S transition in rat hepatocytes, was obtained by tryptic hydrolysis of human a2-macroglobulin followed by ultrafiltration at pH 10. It was purified by high-performance liquid chromatography on MBondapak CI8 and pBondapak NH2 with a practically quantitative yield; from 5.1 g of a2-macroglobulin, 2.8 pg of purified compound were recovered. Inactivation by specific enzymes and chemical analyses showed that the inhibitor is a sialylated glycopeptide whose peptide moiety contains a pyroglutamyl residue. Its molecular mass, estimated by gel permeation chromatography, would be in the interval 3,50&4,600. However, amino acid analyses indicated that it is not yet pure. All these data suggest that a,-macroglobulin could be the carrier of the precursor form of the glycopeptide.