The American Crystallographic Association recently featured work conducted by NDSU crystallographers Christopher Colbert and Sangita Sinha, both assistant professors of chemistry and biochemistry.
Colbert and Sinha’s work in protein crystallography was presented at the association’s 2013 annual meeting. It was then highlighted in RefleXions, the association’s quarterly newsletter. To view the newsletter, visit www.amercrystalassn.org
/documents/2013FallNewsWeb.pdf.
Colbert’s research, titled “Structural Characterization of Pandoraea Pnomenusa B-356 Biphenyl Dioxygenase Reveals Features of a Potent PCB-Degrading enzyme,” was highlighted in the annual meeting’s BioMac Posters section. In this study, Colbert and his coauthors used information from multiple high-resolution structures to understand the mechanism and specificity of this enzyme and to construct a structure-based classification of this enzyme compared to other Rieske oxygenase proteins.
The study led to understanding the superior ability of some enzymes to degrade polychlorinated biphenyls, which are important environmental pollutants. Further, based on this information the authors were able to design mutations to improve the reactivity of biphenyl dioxygenase oward, a wider variety of polychlorinated biphenyls. Sinha also contributed to this work, which is now published in the journal PLoS One at www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0052550.
Sinha presented a seminar, titled “Targeting the g-herpesvirus mediated inhibition of autophagy,” in the scientific session on Host Pathogen Interactions.
The g-herpesviruses are cancer-causing viruses that also cause human diseases like infectious mononucleosis. Sinha’s work has explained the mechanism by which a protein encoded by the g-herpesvirus down-regulates autophagy, a critical cellular degradation pathway that protects the cell from pathogens.
The seminar reported recent results obtained by Sinha’s graduate students Minfei Su and Yang Mei, wherein they combined information from cellular and biochemical experiments to develop and test a peptide that selectively inhibits g-herpesvirus down-regulation of autophagy, but does not interfere with normal cellular regulation. The mechanism by which the peptide is bound by the viral protein was found by determining the atomic structure of the viral protein-peptide complex. This peptide could provide a basis for the development of therapeutics targeting g-herpesvirus infections.
Colbert also contributed to this work, which has recently been published in the Journal of Biological Chemistry at www.jbc.org/content/early/2014/01/17/jbc.M113.515361.full.pdf.
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