Structural and dynamic characterization of 2/2 hemoglobins

Johns Hopkins University, Baltimore MD

Investigators

Abstract

Intellectual merit The physical properties of globular proteins are a topic of intense investigation and practical importance. Multiple approaches have been deployed to understand the determinants of stability and plasticity of these vital biomolecules. Among the methods that are most useful, but so far much underutilized, is nuclear magnetic resonance spectroscopy (NMR) at high pressure. The combination of gentle perturbation and residue-level description afforded by this technique has excellent potential for exposing novel architectural principles in proteins. The proposed research will combine molecular biology, amino acid sequence analysis, and high-pressure NMR methods to explore the native state of a set of monomeric bacterial and algal hemoglobins. The work will investigate the original notion that a common internal cavity network is a crucial entity governing conformational changes concerted with ligand binding and volume dynamics. Studies will be extended to related proteins from organisms that live in high pressure environments to enhance the description of the molecular attributes of globins functioning under extreme conditions of pressure and low temperature. Because the globins of interest are enzymatic and of ancient origin, the results will pertain to multiple fields of inquiry besides protein physical chemistry, including phylogenetics, heme chemistry, and molecular evolution. These ramifications offer an opportunity for laboratory and classroom training of students with diverse interests. Broader impact The broader impact of the proposed research will be achieved through a combination of teaching, training, outreach, and dissemination. Research results will be incorporated in a biophysics undergraduate course in spectroscopy and in a graduate course in biophysical methods. Training will be provided to graduate and undergraduate students, including REU summer students, working directly on the project. Participation in outreach activities will include lab tours for high-school students along with research and career presentations to attract women and underrepresented groups to STEM fields. Participation in the Biophysics Research for Baltimore Teens summer program (organized by the Program in Molecular Biophysics of Johns Hopkins University) will focus on introducing selected high-school students of Baltimore City to scientific research. Dissemination will be through publications, lectures at other institutions, participation in conferences, and database depositions.