Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

WWU Graduate School Collection

Theses/Dissertations

Sortase

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Class A Sortases: Structures And Alternative Substrate Binding And Cleavage, Brandon Vogel Jan 2023

Class A Sortases: Structures And Alternative Substrate Binding And Cleavage, Brandon Vogel

WWU Graduate School Collection

Sortases, consisting of classes A-F, are cysteine transpeptidases found in the cell wall of Gram-positive bacteria. They play a crucial role in ligating proteins to the cell wall that are responsible for cell adhesion, immune evasion, host cell invasion, and nutrient acquisition through a transpeptidation reaction. Consequently, they are an attractive therapeutic target. Class A sortases are also utilized in protein engineering applications such as sortase-mediated ligations and sortagging. Despite extensive research in the past two decades, gaps persist in understanding how class A sortases recognize their substrates, primarily due to a lack of structural information on sortases non-covalently bound …


Using Qm/Mm Methods To Explore Sortase Enzyme Intermediates, Kinetics, And Stability, Kyle Whitham Jan 2023

Using Qm/Mm Methods To Explore Sortase Enzyme Intermediates, Kinetics, And Stability, Kyle Whitham

WWU Graduate School Collection

Biochemistry has seen advancements in methods and understanding of the inner workings of proteins, yet biochemists struggle to see real time reaction pathways of protein intermediates. This is where computational chemistry comes in and fills in the holes in knowledge through the use of Quantum Mechanical (QM) models. QM chemistry alone does not give results in a reasonable timescale to predict protein chemistry in a reasonable amount of time. Computational chemistry methods such as Quantum mechanical (QM)/ Molecular Mechanical (MM) (QM/MM), allow us to split the in-silico system into two regions that utilize a fast MM force field region and …


Sortase-Mediated Ligation To Investigate Large Idr-Containing Cytoskeletal Regulators, Melissa Oueld Es Cheikh Jan 2022

Sortase-Mediated Ligation To Investigate Large Idr-Containing Cytoskeletal Regulators, Melissa Oueld Es Cheikh

WWU Graduate School Collection

About 43% of eukaryotic proteins contain intrinsically disordered regions (IDRs) of 40 residues or longer. These proteins modulate key cellular functions such as transcription, translation, and signal transduction. Despite their vital roles, little is known about the properties of large disordered proteins due to the difficulties encountered studying them. Solution nuclear magnetic resonance (NMR) spectroscopy is a unique tool allowing for their analysis but traditionally requires uniform protein labeling with 15N and 13C isotopesresulting in convoluted spectra which obscure any meaningful information on their structures and interactions. To remedy this issue, we aim at developing a procedure to segmentally label …


Engineering Segmentally Labeled Intrinsically Disordered Proteins, Erin Rosenkranz Jan 2021

Engineering Segmentally Labeled Intrinsically Disordered Proteins, Erin Rosenkranz

WWU Graduate School Collection

It has long been accepted that a protein’s fold informs its function, but for the vital proteins that don’t adopt one specified fold, this is uninformative. Intrinsically disordered proteins have non-folded regions (IDRs) in their native functional state, which make up 30% of eukaryotic proteins, perform vital cellular processes and contribute to a multitude of disease states. Yet, IDR’s function, interactions and dynamics remain unknown due to their unstable, dynamic, lengthy and solvent-exposed nature. This, along with their tendency for insolubility and aggregation provide formidable challenges to not only their analysis, but their purification, requiring lengthy optimizations. NMR is valuable …


Engineering Class A Sortases: Activity And Selectivity Of Hybrid And Ancestral Variants, Sarah Struyvenberg Jan 2020

Engineering Class A Sortases: Activity And Selectivity Of Hybrid And Ancestral Variants, Sarah Struyvenberg

WWU Graduate School Collection

Bacterial sortases are cysteine transpeptidases that anchor virulence factors to the surface of bacterial cells. Sortases are a powerful tool utilized for protein engineering that allow researchers to modify proteins at the protein level, not the DNA level. However, important limitations to utilization of sortases for engineering purposes exist; namely, SrtA from S. aureus is a relatively modest enzyme compared to other SrtA enzymes and is very specific for the LPXTG motif. Previous work from our collaborators and others revealed that sortases from different species can recognize alternative sequences and that activities can vary widely. We were curious about how …


Progress Towards The Substrate-Bound Structure Of Streptococcus Pneumoniae Sortase A, Nicholas M. Horvath Jan 2019

Progress Towards The Substrate-Bound Structure Of Streptococcus Pneumoniae Sortase A, Nicholas M. Horvath

WWU Graduate School Collection

Sortases are cysteine transpeptidases found primarily on the cell surface of Gram-positive bacteria. Sortase-mediated ligations have become an attractive option for protein modification chemistry, enabling the synthesis of a wide range of non-natural polypeptide derivatives. Attempts at understanding how these enzymes recognize and bind substrates are integral to furthering their usefulness in protein engineering and, potentially, treatment of bacterial diseases. However, the variable substrate specificity and activity between homologs of these enzymes is not yet fully understood. Of specific interest to us is sortase A from Streptococcus pneumoniae (SrtApneu), as it demonstrates a broad substrate tolerance not …