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Updated: Aug 15, 2026
Defining Substrate Specificities for Lipase and Phospholipase Candidates
Published on: November 23, 2016
Identification of three competitive inhibitors for membrane-associated, Mg2+-dependent and neutral 60 kDa
Seok Kyun Kim1, Sang Mi Jung, Kyong Hoon Ahn
1Department of Environmental & Health Chemistry, College of Pharmacy, Chung-Ang University, Dongjak-Ku, Seoul 156-756, Korea.
Abstract:
Methanol extracts of domestic plants of Korea were evaluated as a potential inhibitor of neutral pH optimum and membrane-associated 60 kDa sphingomyelinase (N-SMase) activity. In this study, we partially purified N-SMase from bovine brain membranes using ammonium sulfate. It was purified approximately 163-fold by the sequential use of DE52, Butyl-Toyopearl, DEAE-Cellulose, and Phenyl-5PW column chromatographies. The purified N-SMase activity was assayed in the presence of the plant extracts of three hundreds species. Based on the in vitro assay, three plant extracts significantly inhibited the N-SMase activity in a time- and concentration-dependent manner. To further examine the inhibitory pattern, a Dixon plot was constructed for each of the plant extracts. The extracts of Abies nephrolepis, Acer tegmentosum, and Ginkgo biloba revealed a competitive inhibition with the inhibition constant (Ki) of 11.9 microg/ mL, 9.4 microg/mL, and 12.9 microg/mL, respectively. These extracts also inhibited in a dose-dependent manner the production of ceramide induced by serum deprivation in human neuroblastoma cell line SH-SY5Y.
