Analytical Chemistry Commons^™

Demonstration Of A Targeted Proteome Characterization Approach For Examining Specific Metabolic Pathways In Complex Bacterial Systems, Adam Justin Martin

Masters Theses

Multiple Reaction Monitoring (MRM) is a powerful tandem mass spectrometry (MS/MS) tool frequently implemented in proteomic studies to provide targeted analysis of proteins and peptides. The selectivity that MRM delivers is so strong that it provides the quadrupole mass spectrometers (QQQ), on which it is commonly employed, with pertinence to proteomic studies that they would otherwise lack for their relatively low resolution. Additionally, this increased level of selectivity is sufficient enough to supplant complicated fractionation techniques, additional dimensions of chromatography, and 24 hour long MS/MS experiments in simplistic biological samples. But there is a deficiency of evidence to determine the …

Resonance Hyper-Raman Characterization Of Nonlinear Chromophores, Christopher Bennett Milojevich

Doctoral Dissertations

Hyper-Raman spectroscopy is a nonlinear optical probe which can be used to explore the multi-photon properties of molecules. Three studies are presented in this dissertation. The first study is a combined experimental investigation of the surfaceenhanced hyper-Raman scattering with a theoretical study of the electronic states of the Rhodamine 6G molecule. This study demonstrates that hyper-Raman spectroscopy can be used to probe electronic states which are one-photon inaccessible. The second study involves a comparison of experimentally measured resonance hyper-Raman spectra to first-principles calculations of the resonance hyper-Raman scattering. This study shows the utility of coupling hyper-Raman spectroscopy and hyper-Raman calculations …

Quorum Sensing And Metabolism In Marine Environments, Amanda May

Doctoral Dissertations

Quorum sensing (QS) is a phenomenon that allows bacteria to communicate with each other. Small molecules known as autoinducers are synthesized and released by bacteria, and once enough members of the community are around to ensure survival, i.e. quorum, a phenotype, e.g. bioluminescence, is expressed. There are two types of QS molecules, intra- and inter-species.

S-4,5-Dihydroxy-2,3-pentanedione (DPD) is a byproduct of the activated methyl cycle which recycles methionine. This has led to the discussion as to whether DPD is a metabolic byproduct or is the interspecies signal as proposed previously. The detection and quantitation of DPD however, has not …

Analysis Of Ecological Change In Marine Ecosystems Via Novel Imaging And Spectroscopic Techniques On Microalgae Cells, Morgan Breonne Mcconico-Lewis

Doctoral Dissertations

With the increase in anthropogenic pollutants such as: atmospheric CO₂ [carbon dioxide], fossil fuel combustion and fertilizer run off, the fate of the environment is of great importance. Through industrialization, the greenhouse gas, CO₂, is a major contributor to global warming; while nitrogen based fertilizer, causes the production of toxins due to harmful algal blooms. Both chemical impacts dissolve into marine ecosystems effecting the chemical composition of organisms such as microalgae. Microalgae remediate these changes by sequestering carbon and nitrogen; thus there is a need to understand how these impacts affect the ecosystem by detecting the change …

Relative And Absolute Quantitation Of Metabolites And Lipids Using Lc/Ms/Ms On The Tsq Quantum Discovery Max, Jesse Lee Middleton

Masters Theses

Two biological systems were studied using LC/ESI/MS/MS on a triple quadrupole operated in SRM (selected reaction monitoring) scan mode. The first bacterium system is aquatic and microscopic in size known as Roseobacter. The second mammalian system is terrestrial and large in size relative to humans known as Holstein cows.

Roseobacter is a clade of marine bacteria abundant in the ocean. Roseophages are viruses that infect Roseobacter and cause viral lysis. Sulfitobacter sp. 2047 was isolated and infected with Roseophages, and the fold change in the metabolic pool relative to a control was studied at discrete time points. The absolute concentration …