Purification of a novel apolipoprotein H-like milk protein with ribonucleolytic and cell-free translation inhibitory activities

Authors
Citation
Xy. Ye et Tb. Ng, Purification of a novel apolipoprotein H-like milk protein with ribonucleolytic and cell-free translation inhibitory activities, LIFE SCI, 67(8), 2000, pp. 887-894
Citations number
17
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
LIFE SCIENCES
ISSN journal
0024-3205 → ACNP
Volume
67
Issue
8
Year of publication
2000
Pages
887 - 894
Database
ISI
SICI code
0024-3205(20000714)67:8<887:POANAH>2.0.ZU;2-N
Abstract
A new whey protein designated apolipoprotein H-like whey protein, with a mo lecular weight of 62 kDa and an N-terminal amino acid sequence similar to t hat of apolipoprotein H, was isolated from bovine milk. The isolation proce dure involved removal of globulin from acid whey by precipitation with 1.8M (NH4)(2)SO4, followed by addition of (NH4)(2)SO4 to attain a concentration of 3.6M. Subsequent steps included chromatography on CM-Sepharose and Mono S and elution of the adsorbed protein of interest with a linear NaCl gradi ent. The new whey protein displayed some ribonuclease (RNase) activity. It was most active at pH 7.5 with yeast transfer RNA (tRNA) as substrate and s howed potent specific ribonuclcolytic activity toward poly C, It inhibited cell-free translation in a rabbit reticulocyte lysate system with an IC50 o f approximately 63 nM. (C) 2000 Elsevier Science Inc. All rights reserved.