MALDI-TOF MS as a label-free approach to rapid inhibitor screening

Journal Article · Thu Jun 15 04:00:00 EDT 2006 · Journal of the American Society for Mass Spectrometry

DOI:https://doi.org/10.1016/J.JASMS.2006.02.019· OSTI ID:22774046

Zhou, Songtao; Burt, Thomas M.; Carr, Andrew N.; Dolan, Elizabeth; Easwaran, Vijayasurian; Evdokimov, Artem; Kawamoto, Richard; Roesgen, Jeff; Davis, Gregory F. ^[1]

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1. Procter and Gamble Pharmaceuticals, Health Care Research Center (United States)

Mass Spectrometry (MS) has been widely reported for measuring the conversion of substrates to products for enzyme assays. These measurements are typically performed by time-consuming LC-MS to eliminate buffer salts that interfere with electrospray ionization MS. However, matrix-assisted laser desorption ionization, time-of-flight MS (MALDI-TOF MS) offers a label-free and direct readout of substrate and product, a fast sampling rate, and is tolerant of many buffer salts, reagents, and compounds that are typically found in enzyme reaction mixtures. In this report, a demonstration of how MALDI-TOF MS can be used to directly measure ratios of substrates and products to produce IC{sub 50} curves for rapid enzyme assays and compound screening is provided. Typical reproducibility parameters were <7% RSD—a value comparable to ESI MS quantitative assays and well within the acceptable limits for screening assays. The speed of the MALDI readout is currently about 10 s per sample, thus allowing for over 7500 samples/day. From a simplicity standpoint, the enzymatic reaction mixtures are prepared by liquid handling robots, the reactions are stopped by addition of a 10 times volume of acidic matrix solution, and the samples are simultaneously transferred to MALDI target plate for analysis. Importantly, the ratios of substrate to product are of sufficient reproducibility to eliminate the need for internal standards and, thus, minimize the cost and increasing the speed of assay development.

• OSTI ID: 22774046
• Journal Information: Journal of the American Society for Mass Spectrometry, Journal Name: Journal of the American Society for Mass Spectrometry Journal Issue: 6 Vol. 17; ISSN JAMSEF; ISSN 1044-0305
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
COMPARATIVE EVALUATIONS
DESORPTION
IONIZATION
LASER RADIATION
MASS SPECTROSCOPY
MATHEMATICAL SOLUTIONS
READOUT SYSTEMS
SUBSTRATES
TIME-OF-FLIGHT METHOD