کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1174410 | 961748 | 2012 | 8 صفحه PDF | دانلود رایگان |
The unique and physiologically vital bacterial enzyme, prolipoprotein diacylglyceryl transferase (Lgt), which catalyzes the committed first step in the posttranslational transfer of diacylglyceryl group from phosphatidylglycerol to the prospective N-terminal cysteine of prolipoproteins, remains to be characterized for want of a simpler but equally sensitive nonradioactive assay. We, for the first time, report a coupled enzymatic fluorescence assay for Lgt using the de novo synthetic peptide substrate MKATKSAVGSTLAGCSSHHHHHH. The assay is based on the conversion of the by-product, glycerol-1-phosphate, to dihydroxyacetone using an alkaline phosphatase–glycerol dehydrogenase combination and estimating the fluorescence of the coupled reduction of resazurin to resorufin. The minimum amount of glycerol-1-phosphate, and hence the modified peptide, detected by this method is approximately 20 pmol, thereby making this assay a promising alternative to the radioactive assays. The assay is rapid, more convenient, less laborious, and suitable for purification and characterization of Lgt.
Journal: Analytical Biochemistry - Volume 423, Issue 1, 1 April 2012, Pages 163–170