Nanostructure-initiator mass spectrometry (NIMS) technologies for the characterization of microbial activities and enzyme kinetics

Technical advances in DNA sequencing and manipulation have led to an explosion in the sequenced universe and the ability to create libraries of millions of probable enzymes. However, defining the functions of these remains slow and tedious. One factor hindering the high-throughput characterization of enzymes and engineered microbes is the available suite of biochemical monitoring methods. This talk will focus on technologies for mass spectrometry based imaging (MSI) using nanostructure-initiator mass spectrometry (NIMS) to identify gene function and characterize enzyme kinetics in high-throughput.

NIMS is a unique approach to laser desorption/ionization, based on a liquid coated nanostructured surface [1]. Since the coating molecule used is perfluorinated, this allows the retention of modified enzymatic substrates on the surface by using fluorous-phase interactions. And by integrating acoustic sample deposition with NIMS imaging, we are able to measure multiple enzymatic reactions in a high-throughput manner, which is 10- to 100-fold faster than conventional MS-based enzyme assays [2]. In our lab, we applied these technologies for the high-throughput functional characterization of glycosylhydrolases (GHs), were 10,000 different sample conditions were tested for activity mass-tagged substrates [3]. Recently, we have used a oxime-tag to detect soluble reaction products and applied this to quantify the derivatized glycans by GHs [4]. In order to analyze large MSI datasets, we are using the OpenMSI platform and have developed a software application to analyze spatially defined samples [5]. Overall, NIMS-based technologies enable a wide range of large-scale studies on, among others, gene function elucidation/characterization.