Prelim Defense – Nate Morgan

About the event

Speaker: Nathaniel Morgan

Group: Dr. Brian Clowers

Title: Developing Gas-phase Strategies for Annotating Metalloprotein Binding Characteristics

Abstract: Lanmodulin (LanM) is a metalloprotein that exhibits structural changes when binding metals, particularly Lanthanides (Lns), whereupon binding the protein changes from a diffuse, disordered structure into a well-defined rigid conformation. While LanM structural and affinity studies have been conducted previously by other groups, they have been inherently limited by solution-phase measurement constraints and a lack of site-specificity in determining which of the EF-hand motifs is responsible for binding particular metals. Ion Mobility-Mass Spectrometry (IM-MS) provides an avenue for gas-phase ion measurements which lend insight into many structural characteristics that cannot be otherwise obtained. Aim 1 of this work will focus on both IMS to qualitatively provide an endpoint for titrations to obtain affinity information, and collision-induced dissociation (CID) to quantify relative binding energies. Aim 2 will utilize gas-phase Hydrogen-Deuterium Exchange (gHDX) to probe the external surface by quantifying the differences in gHDX rates. Aim 3 will employ ultraviolet photodissociation to fragment LanM ions within an ion trap MS, a method for generating fragment ions that is sufficiently fast to ensure no intra-ion atom migration. Analyzing these fragments in tandem with IMS to confirm binding within the precursor protein ion will allow for annotation of the placement of both metals bound within the protein and locations of deuterium incorporation. The completion of these aims will provide a foundation for a binding analysis workflow for future biomimetic molecules based on the structure of LanM.