Impact of Established and Emerging Software Tools on the Metabolite Identification Landscape.

Scientists' ability to detect drug-related metabolites at trace concentrations has improved over recent decades. High-resolution instruments enable collection of large amounts of raw experimental data. In fact, the quantity of data produced has become a challenge due to effort required to convert raw data into useful insights.

Simultaneous inhibition assay for human and microbial kinases via MALDI-MS/MS.

Selective inhibition of one kinase over another is a critical issue in drug development. For antimicrobial development, it is particularly important to selectively inhibit bacterial kinases, which can phosphorylate antimicrobial compounds such as aminoglycosides, without affecting human kinases. Previous work from our group showed the development of a MALDI-MS/MS assay for the detection of small molecule modulators of the bacterial aminoglycoside kinase APH3'IIIa.

A matrix-assisted laser desorption/ionization tandem mass spectrometry method for direct screening of small molecule mixtures against an aminoglycoside kinase.

Aminoglycoside phosphotransferase 3'IIIa (APH3'IIIa) is a bacterial enzyme involved in antibiotic resistance through phosphorylation of aminoglycosides, which can potentially be overcome by co-administration of an APH3'IIIa inhibitor with the antibiotic. Current assay methods for discovery of APH3'IIIa inhibitors suffer from low specificity and high false positive/negative hit rates. Here, we describe a method for screening APH3'IIIa inhibitors based on direct detection of kanamycin A phosphorylation using MALDI-MS/MS, which is more rapid than conventional assays and does not require secondary assays or sample cleanup.