Moretti R, Thorson JS. A comparison of sugar indicators enables a universal high-throughput sugar-1-phosphate nucleotidyltransferase assay.
Anal Biochem 2008;
377:251-8. [PMID:
18387352 PMCID:
PMC2442561 DOI:
10.1016/j.ab.2008.03.018]
[Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 03/11/2008] [Accepted: 03/12/2008] [Indexed: 10/22/2022]
Abstract
A systematic comparison of six sugar indicators for their sensitivity, specificity, cross-reactivity, and suitability in the context of crude lysates revealed para-hydroxybenzoic acid hydrazide (pHBH) to be best suited for application in a plate-based phosphatase-assisted universal sugar-1-phosphate nucleotidyltransferase assay. The addition of a general phosphatase to nucleotidyltransferase reaction aliquots enabled the conversion of remaining sugar-1-phosphate to free sugar, the concentration of which could be rapidly assessed via the pHBH assay. The assay was validated using the model glucose-1-phosphate thymidylyltransferase from Salmonella enterica (RmlA) and compared favorably with a previously reported HPLC assay. This coupled discontinuous assay is quantitative, high throughput, and robust; relies only on commercially available enzymes and reagents; does not require chromatography, specialized detectors (e.g., mass or evaporative light scattering detectors), or radioisotopes; and is capable of detecting less than 5 nmol of sugar-1-phosphate. It is anticipated that this high-throughput assay system will greatly facilitate nucleotidyltransferase mechanistic and directed evolution/engineering studies.
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