Development,Validation, and Application of a Novel Method for Mammalian Sphingomyelin Synthase Activity Measurement |
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Abstract: | Sphingomyelin synthase (SMS) is a key enzyme for the synthesis of mammalian sphingomyelin. The use of SMS plays diverse roles in physiology and pathology; thus, it could be a useful disease marker and/or drug target. We report here a novel and sensitive method for SMS activity measurement. Using a HPLC column (C18-RP), SMS activity was monitored by measuring a decrease of the fluorescent substrate C6-4-nitrobenzo-2-oxa-1,3-diazole (NBD)-ceramide (C6-NBD-Cer) and increase of the product (C6-NBD-SM). Time- and protein-dependent formation of C6-NBD-SM was investigated and enzyme kinetics was determined K m = 7.49 ± 0.48 µM (C6-NBD-Cer) and V max = 27.86 ± 0.73fmol/h/mg homogenate protein]. This method is feasible, rapid, accurate, highly reproducible, and suitable for quantifying SMS enzyme activity in SMS inhibitor screening studies. A known SMS inhibitor, D609, was employed to evaluate the assay and its IC50 value has been determined. Supplementary materials are available for this article. Go to the publisher's online edition of Analytical Letters for the following free supplemental resources: Tables and figures] |
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Keywords: | C6-NBD-ceramide C6-NBD-sphingomyelin HPLC Inhibitor Sphingomyelin synthase |
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