title: Purification and characterization of a ribonuclease from the wild edible mushroom Armillaria luteo-virens.
abstract: A 15 kDa ribonuclease (RNase) was purified from dried fruiting bodies of the wild edible mushroom Armillaria luteo-virens. The simple 4-step purification protocol involved ion-exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion-exchange chromatography on SP-Sepharose and a final gel filtration by FPLC on Superdex-75. The RNase was unadsorbed on Affi-gel blue gel, but adsorbed on DEAE-cellulose and SP-Sepharose. The N-terminal amino acid sequence of purified RNase was AGVQYKLTILLV, which showed low sequence homology to those of previously reported RNases. The optimal pH and temperature of the enzyme were very close to 4.0 and 70 degrees C, respectively. The enzyme showed considerably high ribonucleolytic activity and broad specificity towards polyhomoribonucleotides, with a specificity of poly(U) > poly(C) > poly (G) > poly(A). The ribonucleolytic activities towards poly(U), poly(C), poly(G) and poly(A) were 279.5, 184.1, 69.9 and 52.3 U/mg, respectively.
authors.affiliation: State Key Laboratory for Agrobiotechnology,d Department of Microbiology, China Agricultural University, Beijing 100193, China.
authors.forename: Li-Jing
authors.initials: LJ
authors.lastname: Xu
authors.forename: Qing-Jun
authors.initials: QJ
authors.lastname: Chen
authors.forename: He-Xiang
authors.initials: HX
authors.lastname: Wang
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Zhang
mesh_terms: D000363:Agaricales / Q000201:enzymology*; D000818:Animals; D004789:Enzyme Activation; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D012260:Ribonucleases / Q000737:chemistry* / Q000302:isolation & purification*; D013379:Substrate Specificity
chemical_list: D005656:Fungal Proteins; D012260:Ribonucleases