• The Korean Journal of Physiology and Pharmacology
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• v.20 no.2
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• pp.177-183
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• 2016

We fortuitously observed a human neutrophil intracellular free-calcium concentration ($[Ca^{2+}]_i$) increasing activity in the commercially available phosphodiesterase I (PDE I), which is actually dried crude venom of Crotalus atrox. As this activity was not observed with another commercially available pure PDE I, we tried to find out the causative molecule(s) present in 'crude' PDE, and identified Lys49-phospholipase A2 (Lys49-PLA2 or K49-PLA2), a catalytically inactive protein which belongs to the phospholipase A2 family, by activity-driven three HPLC (reverse phase, size exclusion, reverse phase) steps followed by SDS-PAGE and LC-MS/MS. K49-PLA2 induced $Ca^{2+}$ influx in human neutrophils without any cytotoxic effect. Two calcium channel inhibitors, 2-aminoetoxydiphenyl borate (2-APB) ($30{\mu}M$) and SKF-96365 ($20{\mu}M$) significantly inhibited K49-PLA2-induced $[Ca^{2+}]_i$ increase. These results suggest that K49-PLA2 modulates $[Ca^{2+}]_i$ in human neutrophils via 2-APB- and SKF-96365-sensitive calcium channels without causing membrane disruption.

• Journal of Life Science
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• v.16 no.1
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• pp.17-21
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• 2006

The effects of Korean and Japanese radishes on inflammatory reaction that involves arachidonic acid cascades were investigated in human epithelial gastric cell. The activities of type I (porcine pancreas) and type II (Crotalus atrox) phospholipase $A_2(PLA_2$) were inhibited by radish. Cyclooxygenase-2 (COX-2) activity was significantly suppressed by radish (p<0.05, p<0.01 and p<0.005). The nitric oxide production was also inhibited by radish. The Korean radish was more effective in inhibition of $PLA_2$ and COX-2 activities and nitric oxide production than Japanease radish. These results indicate that radish has a protective effect on gastric epithelial cell inflammation by suppressing the activities of $PLA_2$ and COX-2 activities and nitric oxide production from gastric epithelial cell.