2026-09-21T12:38:18Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/117595 2023-07-11 col_2142_5131 col_2142_14795 com_2142_5130 com_2142_14794 com_2142_14793 com_2142_8903

Sweedler, Jonathan Sweedler, Jonathan Nair, Satish Procko , Erik Zhao, Huimin 2022-12 application/pdf en text Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-12-01 The student, Kisurb Choe, accepted the attached license on 2022-12-01 at 23:45. The student, Kisurb Choe, submitted this Dissertation for approval on 2022-12-01 at 23:59. This Dissertation was approved for publication on 2022-12-02 at 16:17. DSpace SAF Submission Ingestion Package generated from Vireo submission #18732 on 2023-04-12 at 11:36:48 Modification of substrate specificity of thioesterase, reductase, desaturase by MALDI-tof-MS analysis of microbial colonies Choe, Kisurb 2022-12-02 Enzymes Mass Spectrometry Maldi-ms Chemical heterogeneity in biological systems reveal important clues to the inner workings of the fundamental processes such as lipid metabolism and physiology. High throughput screening of microbes and mutant libraries resolve such complexities enabling multiple biochemical studies such as directed evolution, functional genomics, microbial identification, and genome mining. A promising screening approach is measurement of biochemical products directly from microbial colonies via optically guided matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Measuring the compounds from microbial colonies bypasses liquid culture while minimizing the automation processes, and the wide chemical coverage and the high sensitivity of MALDI-MS can enable diverse biochemical screening projects such as modifying enzymes and functional genomics survey of gene activation/inhibition libraries. The thesis first presents the informatics and the experimental methods that were created to develop the MALDI-MS based colony screen. The macroMS software was developed to perform informatics tasks such as image analysis finding samples, MALDI-MS automation targeting the samples, and data analysis / visualization to find an analyte of interest. Then an experimental method for colony sample preparation, constructing sprayer for applying MALDI matrix, and running MALDI-MS is described. Based on the colony screening method, random libraries of an acyl-ACP thioesterase, an acyl-ACP desaturase, an acyl-CoA reductase were scanned, revealing novel variants with increased specificity for specific products. Thesis eng https://hdl.handle.net/2142/117595 Copyright 2022 Kisurb Choe Ph.D. Dissertation Biochemistry University of Illinois at Urbana-Champaign Biochemistry