Browsing by Author "Mattice, Jenna Rose"

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Changing shape: an investigation into allostery and protein conformational ensembles
(Montana State University - Bozeman, College of Letters & Science, 2023) Mattice, Jenna Rose; Chairperson, Graduate Committee: Brian Bothner; This is a manuscript style paper that includes co-authored chapters.
Allostery is the mechanism by which action at one site on a protein causes a functional change at a distant site. An allosteric change can manifest as conformational change or a change in protein dynamics. In this way, the study of allostery, protein dynamics, and structural biology are individual, yet related fields. Progress and technical advancements in one field inform and drive the others. In this thesis, four protein complexes 2-ketopropyl-coenzyme M oxidoreductase/carboxylase (2-KPCC), acetone carboxylase (AC), Replication protein A (RPA), and Radiation sensitive 52 (Rad52) were studied to elucidate conformational change and allostery during catalysis. A variety of orthogonal biophysical approaches were used to study these systems. To infer changes in protein dynamics and conformation, hydrogen-deuterium exchange coupled to mass spectrometry was used in three of these studies. This technique allows for the probing of the hydrogen bonding network based on ligand binding or mutation. Probing of AC, RPA and Rad52 has led to the description of conformational changes essential for function. Ion mobility coupled to native mass spectrometry was used to investigate the available conformations of 2-KPCC during catalysis and led to the discovery of residues essential for modulating those conformations. The concepts of allostery, conformational ensemble, and protein dynamics have evolved since they were first described. Utilizing mass spectrometry-based techniques, my work helped expand the knowledge of several protein systems that contain allosteric networks which are necessary for function. The studies presented in this thesis increase the understanding not only for these protein systems, but also of protein function on a deeper level.
The reactive form of a C-S bond-cleaving CO 2-fixing flavoenzyme
(Montana State University - Bozeman, College of Letters & Science, 2019) Mattice, Jenna Rose; Chairperson, Graduate Committee: Jennifer DuBois; Thesis includes a paper of which Jenna R. Mattice is not the main author.
Atmospheric carbon dioxide (CO 2) is used as a carbon source for building biomass in plants and most engineered synthetic microbes. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), the most abundant enzyme on earth, is used by these organisms to catalyze the first step in CO 2 fixation. 1,2 Microbial processes that also fix carbon dioxide or bicarbonate have more recently been discovered. My research focuses on a reaction catalyzed by 2-KPCC (NADPH:2-ketopropyl-coenzyme M oxidorectuase/ carboxylase), a bacterial enzyme that is part of the flavin and cysteine-disulfide containing oxidoreductase family (DSORs) which are best known for reducing metallic or disulfide substrates. 2-KPCC is unique because it breaks a comparatively strong C-S bond, leading to the generation of a reactive enolacetone intermediate which can directly attack and fix CO 2. 2-KPCC contains a phenylalanine in the place where most other DSOR members have a catalytically essential histidine. This research focuses on studying the unique reactive form of 2-KPCC in presence of an active site phenylalanine.