title: Purification and characterization of a ubiquitin-like peptide with macrophage stimulating, antiproliferative and ribonuclease activities from the mushroom Agrocybe cylindracea.
abstract: A peptide, with a molecular mass of 9.5kDa and demonstrating an N-terminal sequence similar to ubiquitin, was isolated from fruiting bodies of the mushroom Agrocybe cylindracea. The peptide was isolated with a purification protocol involving ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, FPLC-ion exchange chromatography on Mono S and FPLC-gel filtration on Superdex 75. The peptide was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and Mono S. It showed antiproliferative activity on leukemia cell line (M1) and hepatoma cell line (HepG2), and enhanced nitric oxide production in murine peritoneal macrophages with a potency comparable to that of lipopolysaccharide. A pH of 6.0 was required for optimal RNase activity. Its RNase activity was stable over the temperature range of 0-60 degrees C. It exerted ribonucleolytic activity preferentially on polyC, much lower activity on polyU, and negligible activity on polyA and polyG.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, The Chinese University of Hong Kong, New Territories, Shatin, Hong Kong, PR China.
authors.forename: Patrick H K
authors.initials: PH
authors.lastname: Ngai
authors.forename: H X
authors.initials: HX
authors.lastname: Wang
authors.forename: T B
authors.initials: TB
authors.lastname: Ng
mesh_terms: D000363:Agaricales / Q000737:chemistry*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D006358:Hot Temperature; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D010455:Peptides / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D012260:Ribonucleases / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D014452:Ubiquitins / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D010455:Peptides; D014452:Ubiquitins; D009569:Nitric Oxide; D012260:Ribonucleases