Award: OCE-1233589

Proteins accounts for a major portion of the material in most living cells and its synthesis and expression is a fundamental property of all living things. As such its response during growth and to the environment has many implications for multiple fields of science especially the cycling of proteins in the ocean. A full understanding of the actual extent of protein cycling in marine systems faces at least three major impediments: 1) the potential number of proteins is vast, yet often unknown, 2) exposure to biological and chemical catalysts during organic recycling reactions can alter or modify the original protein structure, obscuring its identification and 3) bacteria are the major agents for changes in proteins but are very dynamic in their work on protein hydrolysis, resynthesize, and modification. In order to quantitatively or (even) qualitatively follow proteins and their potential for preservation under environmentally realistic conditions, we must be able to determine protein or peptide sequences over a broad continuum of complex structures and conditions in the environment. This study linked two fields which do not often overlap to better understanding of the cycling of proteins in the ocean. The first was marine organic geochemistry which seeks to understand the chemistry of organic materials produced and recycled the ocean. The focus is often on individual molecules and what insight they can provide into the cycling of elements. The second field is proteomics, the study of proteins which is based on biomedical analysis of thousands of proteins in a single sample. By linking marine organic geochemistry and environmental proteomics, this project provided a case study of an approach which combines two diverse fields to address essential questions for the cycling of a major component of the living ocean that needed intense analytical work and statistical analysis. By better defining the proteins in ocean systems, we can asked questions about major element cycling and the response of specific groups of organisms to their environment. The findings for this work showed that among the thousands of possible proteins, a select few are not rapidly recycled in the surface ocean waters, but eventually are preserved in the surface sediments. These protein are protected from recycling by both physical measures as well as chemical cross links which slow their losses. Bacterial are very active in the process and contribute their own distinctive distribution proteins which appear over time. A major part of this work was to develop analytical tools for analysis and the statistical interpretation of the thousands of proteins identified in marine systems and laboratory experiments using marine bacteria, training both graduate students and undergradutes along the way. These results made important progress in our ability to identify the proteins in the environment and trace their origins with confidence. Last Modified: 01/09/2017 Submitted by: H. Rodger Harvey