Chemistry Commons^™

Computational And Analytical Modelling Of Droplet-Macroion Interactions, Myong In Oh

Electronic Thesis and Dissertation Repository

Charged droplets involving macromolecules undergo distinct disintegration mechanisms and shape deformations as a consequence of droplet-macroion interactions. Three general classes of droplet-macroion interactions that have been identified in the Consta group are: contiguous extrusion of a linear macroion from a droplet, "pearl-necklace" droplet conformations, and "star"-shaped droplets. This dissertation probes in a systematic manner the onset and various outcomes of macroion-droplet interactions, using atomistic molecular dynamics and realistic examples of solvent and macromolecules.

When the charge-squared-to-volume ratio of a droplet is below but near a threshold value, certain flexible macromolecules, such as poly(ethylene glycol), extrude from a droplet, induced by …

Investigations Into The Role Of Conformational Dynamics In Protein Function: Insights From Hydrogen/Deuterium Exchange-Mass Spectrometry, Courtney S. Fast

Electronic Thesis and Dissertation Repository

Deciphering protein structure and dynamics is a key prerequisite for understanding biological function. The current work aims to apply HDX-MS to improve the understanding of protein structure and dynamics for systems that remain challenging for other techniques. Following a general overview of the field (Chapter 1), Chapter 2 investigates the relationship between enzyme dynamics and catalysis. By conducting comparative HDX-MS measurements on rM1-PK during substrate turnover and in the resting state, catalytically active rM1-PK undergoes significant rigidification of the active site. However, virtually the same rigidification was seen upon exposing rM1-PK to substrate or product in the …

Molecular Dynamics Simulations Of Charged Nanodroplets, Elias Ahadi

Electronic Thesis and Dissertation Repository

Charged nanodroplets represent a fascinating research area due to their unique dynamics and physical properties. These nanodroplets play a key role in electrospray mass spectrometry (ESI-MS), which is a method for analyzing organic/inorganic molecules as well as proteins and other biomolecular species. The mechanism whereby these analytes are transferred into the gas phase as intact ions remains incompletely understood. Two competing models have been proposed to explain the process, the charged residue model (CRM) and the ion evaporation model (IEM). Under the CRM, evaporation of the droplet proceeds until dryness, at which point the analyte ion is left behind. Under …