摘要：Lactoferricin (LFcin) hydrolyzed from lactoferrin (LF), a major 80 kDa iron-binding protein in milk and other exocrine secretions, was characterized as a potent activator of protein kinase CK2 (CK2) in vitro . Human LFcin (hLFcin) at 0.5 µg stimulated approx. 5-fold CK2 activity [phosphorylation of 60S acidic ribosomal proteins (P0, P1, P2) and Hsp90 (p98)] in a manner similar to other functional proteins with oligo-Arg clusters, such as salmine A1, sperm histone H2B and HIV-1 Rev. Interestingly, this stimulatory effect of hLFcin was significantly reduced when it was phosphorylated by A-kinase in vitro . These results suggest that (i) hLFcin acts as a potent CK2 activator in vitro ; and (ii) the stimulatory effect of hLFcin on CK2 activity is regulated by its phosphorylation by A-kinase in vitro .
关键词：human lactoferricin;cAMP-dependent protein kinase;CK2 activator;protein kinase CK2
