Environmental fate; Proteins; Photochemistry; Amino acids; Natural organic matter
Chu Chiheng, Erickson Paul R., Lundeen Rachel A., Stamatelatos Dimitrios, Alaimo Peter J., Latch Douglas E., McNeill Kristopher (2016), Photochemical and non-photochemical transformations of cysteine with dissolved organic matter, in Environmental Science and Technology
, 50, 6363-6373.
Lundeen Rachel A., Chu Chiheng, Sander Michael, McNeill Kristopher (2016), Photooxidation of the Antimicrobial, Nonribosomal Peptide Bacitracin A by Singlet Oxygen under Environmentally Relevant Conditions, in Environmental Science & Technology
, 50(16), 8586-8595.
Janssen Elisabeth M. L., Marron Emily, McNeill Kristopher (2015), Aquatic photochemical kinetics of benzotriazole and structurally related compounds, in Environ. Sci.: Processes Impacts
, 17(5), 939-946.
Chu Chiheng, Lundeen Rachel A., Sander Michael, McNeill Kristopher (2015), Assessing the Indirect Photochemical Transformation of Dissolved Combined Amino Acids through the Use of Systematically Designed Histidine-Containing Oligopeptides, in Environmental Science & Technology
, 49(21), 12798-12807.
Chu Chiheng, Lundeen Rachel A., Remucal Christina K., Sander Michael, McNeill Kristopher (2015), Enhanced Indirect Photochemical Transformation of Histidine and Histamine through Association with Chromophoric Dissolved Organic Matter, in Environmental Science & Technology
, 49(9), 5511-5519.
Janssen Elisabeth, McNeill Kristopher (2015), Environmental Photoinactivation of Extracellular Phosphatases and the Effects of Dissolved Organic Matter, in Environmental Science and Technology
, 49(2), 889-896.
Janssen Elisabeth M-L, Erickson Paul R, McNeill Kristopher (2014), Dual roles of dissolved organic matter as sensitizer and quencher in the photooxidation of tryptophan., in Environmental science & technology
, 48(9), 4916-24.
Lundeen Rachel A., Janssen Elisabeth M.-L., McNeill Kristopher (2014), Environmental Photochemistry of Amino Acids, Peptides and Proteins, in Chimia
, 68, 812-817.
Lundeen Rachel A., McNeill Kristopher (2013), Reactivity differences of combined and free amino acids: Quantifying the relationship between three-dimensional protein structure and singlet oxygen reaction rates, in Environmental Science & Technology
, 47, 14215-14223.
Amino acids, oligopeptides and proteins are central building blocks of life and of key importance in the biogeochemistry of aquatic systems. In these systems, amino acids at different levels of structural organization are susceptible to oxidation by photochemically generated reactive oxygen species. While photochemical transformation therefore plays a key role in the environmental fate of amino acids, oligopeptides and proteins in surface waters, there are as of yet only few systematic studies on this topic. This proposal aims to fill gaps in our knowledge regarding the environmental photochemistry of amino acid-based compounds in aquatic systems.The specific objectives of this proposal are to (1) Characterize the photochemistry of freely dissolved cysteine, cystine, and of small cysteine-containing oligopeptides; (2) Assess the extent to which humic-sorbed amino acids and peptides experience enhanced phototransformation; (3) Determine the effect of protein structure on the indirect photochemistry of its photolabile amino acid residues; and, (4) Evaluate the effect of oriented protein sorption to humic substances on amino acid photochemistry. The work plan is organized into three Subprojects that will be carried out by two PhD students and a postdoctoral researcher. The expected scientific outcomes include achieving the immediate goal of improving the understanding of amino acid photooxidation in surface waters at the molecular level. This understanding is expected to benefit the larger environmental science communities, from researchers studying sulfur and nitrogen element cycling to those elucidating the role of extracellular enzymes in nutrient acquisition. In addition, we expect to make methodological advances that will aid in the study of macromolecules in natural water and on the sorption of ionogenic organic compounds to natural organic matter. The proposed project will also achieve education outcomes that include the education of two PhD students and training of a postdoctoral researcher. In addition, six related master thesis projects are anticipated. Numerous synergisms are expected to arise from the parallel projects on distinct yet closely related topics.