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Physical Sciences and Mathematics Commons™

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

2020

University of Massachusetts Amherst

Biochemistry, Biophysics, and Structural Biology

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Controlled Membrane Remodeling By Nanospheres And Nanorods: Experiments Targeting The Design Principles For Membrane-Based Materials, Sarah Zuraw-Weston Dec 2020

Controlled Membrane Remodeling By Nanospheres And Nanorods: Experiments Targeting The Design Principles For Membrane-Based Materials, Sarah Zuraw-Weston

Doctoral Dissertations

In this thesis we explore two experimental systems probing the interactions of nanoparticles with lipid bilayer membranes. Inspired by the ability of cell membranes to alter their shape in response to bound particles, we report two experimental studies: one of nanospheres the other of long, slender nano-rods binding to lipid bilayer vesicles and altering the membrane shape. Our work illuminates the role of particle geometry, particle concentration, adhesion strength and membrane tension in how membrane morphology is determined. We combine giant unilamellar vesicles with oppositely charged nanoparticles, carefully tuning adhesion strength, membrane tension and particle concentration. In the case of …

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Investigating The Accumulation, Sub-Organ Distribution, And Biochemical Effects Of Nanomaterials Using Mass Spectrometry, Kristen Nicole Sikora Dec 2020

Investigating The Accumulation, Sub-Organ Distribution, And Biochemical Effects Of Nanomaterials Using Mass Spectrometry, Kristen Nicole Sikora

Doctoral Dissertations

Gold nanoparticles (AuNPs) are attractive materials for use in various biomedical applications, such as therapeutic delivery, due to their unique chemical properties and modular tunability. Mass spectrometry methods, including laser desorption/ionization mass spectrometry (LDI-MS) and inductively coupled plasma mass spectrometry (ICP-MS) have been successfully used to evaluate the distribution of AuNPs in complex biological systems. As new AuNP-based materials are developed for applications in therapeutic delivery, it is essential to simultaneously develop analytical techniques that can comprehensively assess their behavior in vivo. In this dissertation, novel mass spectrometric methods have been developed and utilized to evaluate the uptake, distribution, …

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Study Of The Role Of Biologically-Relevant, Labile Nickel Pools In The Maturation Of Nickel-Dependent Enzymes, Priyanka Basak Sep 2020

Study Of The Role Of Biologically-Relevant, Labile Nickel Pools In The Maturation Of Nickel-Dependent Enzymes, Priyanka Basak

Doctoral Dissertations

Cellular nickel pools, comprised of static and labile pools of nickel complexes, play important roles in maintaining nickel homeostasis in various organisms (microbes, fungi, and plants), which utilize it as a cofactor of one or more nickel enzymes that catalyze specific reactions and are essential for their proper growth and survival in various ecological niches. Like other metals, tight regulation of cellular nickel levels is critical to prevent toxic effects of nickel deprivation, nickel overload, and ‘free’ nickel. While more static nickel pools include nickel tightly bound to nickel-dependent enzymes, nickel in the labile pool is exchangeable and weakly bound …

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Structural Analysis Of Protein Therapeutics Using Covalent Labeling – Mass Spectrometry, Patanachai Limpikirati Jul 2020

Structural Analysis Of Protein Therapeutics Using Covalent Labeling – Mass Spectrometry, Patanachai Limpikirati

Doctoral Dissertations

Using mass spectrometry (MS) to obtain information about a higher order structure of protein requires that a protein’s structural properties are encoded into the mass of that protein. Covalent labeling (CL) with reagents that can irreversibly modify solvent accessible amino acid side chains is an effective way to encode structural information into the mass of a protein, as this information can be read-out in a straightforward manner using standard MS-based proteomics techniques. The differential reactivity of proteins under two or more conditions can be used to distinguish protein topologies, conformations, and/or binding sites. CL-MS methods have been effectively used for …

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Characterization Of Biodistribution Of Transferrin And Receptor Binding Mechanism By Mass Spectrometry, Hanwei Zhao Mar 2020

Characterization Of Biodistribution Of Transferrin And Receptor Binding Mechanism By Mass Spectrometry, Hanwei Zhao

Doctoral Dissertations

Protein-based therapeutics have emerged as a key driver of rapid growth in drug development pipelines. However, developing such protein drugs is not straightforward in most cases, the existence of physiological barriers greatly restricts the efficient delivery of many therapeutic molecules, and therefore limits their clinical applications. A promising way to address this challenge takes advantage of certain transport protein which can effectively across and enhance the permeability of these barriers, such as transferrin (Tf) which can be internalized by malignant cells and cross physiological barriers via transferrin receptor (TfR)-mediated endocytosis and transcytosis. However, developing such products is impossible without successfully …

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Covalent Labeling-Mass Spectrometry For Characterizing Protein-Ligand Complexes, Tianying Liu Feb 2020

Covalent Labeling-Mass Spectrometry For Characterizing Protein-Ligand Complexes, Tianying Liu

Doctoral Dissertations

This dissertation focuses on applying covalent labeling (CL) and mass spectrometry (MS) for characterizing protein-ligand complexes. Understanding protein-ligand interactions has both fundamental and applied significance. Covalent labeling is a protein surface modification technique that selectively modifies solvent-exposed amino acid side chains of proteins. A covalent bond is formed between the functional groups of labeling reagent and protein’s side chain. One of the key factors that affects CL reactivity is a side chain’s solvent accessibility. Ligand binding protects residues on the protein surface from being labeled, and residues involved in ligand binding can be indicated via decreases in labeling extents. The …

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