Characterization of secretory type IIA phospholipase A2 (sPLA2-IIA) as a glycyrrhizin (GL)-binding protein and the GL-induced inhibition of the CK-II-mediated stimulation of sPLA2-IIA activity in vitro.
By means of heparin-affinity and glycyrrhizin (GL)-affinity column chromatographies (HPLC), a GL-binding phospholipase A2 (gbPLA2) was selectively purified from the synovial fluids of patients with rheumatoid arthritis. This purified gbPLA2 was identified as a secretory type IIA PLA2 (sPLA2-IIA) since it was crossreacted with anti-sPLA2-IIA serum. The activity of purified sPLA2-IIA was inhibited by glycyrrhetinic acid (GA) and a GA derivative (oGA) in a dose-dependent manner, but it was more sensitive to GA than GL. Furthermore, it was found that (i) purified sPLA2-IIA is phosphorylated by casein kinase II (CK-II) in vitro; (ii) this phosphorylation induces in a significant stimulation of PLA2 activity; and (iii) oGA at one-tenth the concentration of GL inhibits the CK-II-mediated stimulation of sPLA2-IIA activity. These results show that (i) sPLA2-IIA is a GL-binding protein; and (ii) CK-II mediates stimulation of its PLA2 activity in vitro.
Shimoyama
Y
Y
Laboratory of Genetical Biochemistry, School of Allied Health Sciences, Kitasato University, Sagamihara, Japan.
Sakamoto
R
R
Akaboshi
T
T
Tanaka
M
M
Ohtsuki
K
K
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000378:metabolism* / Q000494:pharmacology*; D001172:Arthritis, Rheumatoid / Q000201:enzymology; D047390:Casein Kinase II; D002853:Chromatography, Liquid; D003435:Crotalid Venoms / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006034:Glycyrrhetinic Acid / Q000494:pharmacology; D019695:Glycyrrhizic Acid / Q000378:metabolism* / Q000494:pharmacology*; D054501:Group II Phospholipases A2; D006801:Humans; D066298:In Vitro Techniques; D010741:Phospholipases A / Q000302:isolation & purification / Q000378:metabolism*; D054467:Phospholipases A2; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors*; D013268:Stimulation, Chemical; D013582:Synovial Fluid / Q000201:enzymology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D003435:Crotalid Venoms; D004791:Enzyme Inhibitors; D019695:Glycyrrhizic Acid; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D010741:Phospholipases A; D054501:Group II Phospholipases A2; D054467:Phospholipases A2; D006034:Glycyrrhetinic Acid