Prasad Reddy

Research Chemist

Kelman Group

Contact

Email: preddy@ibbr.umd.edu

Call: (240) 314-6127

Profile

In the area of microbial forensics and bioterrorism, we are working on the characterization of virulence factors to understand the molecular basis of pathogenesis in Yersinia pestis (plague causing bacteria) and Mycobacterium tuberculosis (tuberculosis disease). We use adenylyl cyclase (AC), one of the virulence factors in Bacillus anthracis (anthrax disease), as a model system to understand the AC’s role in other bacterial pathogens. Adenylyl cyclases (ACs) are classified into four major categories. Class I ACs is from the enteric bacteria such as Escherichia coli, Salmonella typhimuriu, and Yersinia pestis. These prokaryotic Class I ACs are primarily regulated by sugar sensor proteins. Class I AC from Yersinia pestis, the plague causing bacteria and a potential bioterrorism agent, has overwhelming homology (85%) with the E. coli enzyme. Class II ACs are from Bacillus anthracis and Bordetella pertussis. Class II ACs are virulent factors in these two bacterial species. Class II ACs elicit their virulence by producing supraphysiological concentration of cyclic 3’, 5’ adenosine monophosphate as a consequence of the activation of Class II AC by the host calmodulin. Class III ACs are highly complex macromolecules containing two spans of six helical transmembrane domains and two cytoplasmic domains. Class III ACs are regulated by a variety of small molecules such as hormones, guanosine triphosphate, and macromolecular proteins such as guanine nucleotide binding proteins, and calmoduline. Class III A Cs are originally thought to be only from higher eukaryotic origin. But the work from our laboratory has shown that Mycobacterium tuberculosis contains only Class III adenylyl cyclases, albeit half the molecular secondary structure with only one six helical transmembrane domain and one cytoplasmic domain. However the mycobacterial class III AC functions as a dimer mimicking the eukaryotic enzyme. Even more intriguing is the fact that there are 15 genes for adenylyl cyclase spread around the genome of Mycobacterium tuberculosis. We have been performing the gene expression measurements and activity profiles of these 15 adenylyl cyclase genes. Yersinia pestis has a Class IV AC in addition to the Class I AC. Class IV AC is a small protein consisting of only 179 amino acids and functions as a dimer. We have solved the three dimensional structure of Class IV AC.

Publications
2021
Fusing an insoluble protein to GroEL apical domain enhances soluble expression in Escherichia coli.
2018
Supplemental Oxygen Protects Heart Against Acute Myocardial Infarction.
Platform development for expression and purification of stable isotope labeled monoclonal antibodies in Escherichia coli.
2016
Production, Purification, and Characterization of ¹⁵N-Labeled DNA Repair Proteins as Internal Standards for Mass Spectrometric Measurements.
2015
Protein labeling in Escherichia coli with (2)H, (13)C, and (15)N.
Anal Papilloma: An Exceptional Presentation of Fibrocystic Disease in Anogenital Mammary-Like Glands.
Extreme Expression of DNA Repair Protein Apurinic/Apyrimidinic Endonuclease 1 (APE1) in Human Breast Cancer As Measured by Liquid Chromatography and Isotope Dilution Tandem Mass Spectrometry.
2014
The fused anthranilate synthase from Streptomyces venezuelae functions as a monomer.
2013
Identification and quantification of DNA repair protein apurinic/apyrimidinic endonuclease 1 (APE1) in human cells by liquid chromatography/isotope-dilution tandem mass spectrometry.
2012
Identification and quantification of human DNA repair protein NEIL1 by liquid chromatography/isotope-dilution tandem mass spectrometry.
2011
Evidence for upregulated repair of oxidatively induced DNA damage in human colorectal cancer.
Identification and quantification of DNA repair proteins by liquid chromatography/isotope-dilution tandem mass spectrometry using their fully 15N-labeled analogues as internal standards.
Stable isotope-labeling of DNA repair proteins, and their purification and characterization.
2010
Active-site structure of class IV adenylyl cyclase and transphyletic mechanism.
Protein Crystal Engineering of YpAC-IV using the Strategy of Excess Charge Reduction.
2009
Advances in solution- and solid-phase synthesis toward the generation of natural product-like libraries.
Profound asymmetry in the structure of the cAMP-free cAMP Receptor Protein (CRP) from Mycobacterium tuberculosis.
Discovery of indoline-based, natural-product-like compounds as probes of focal adhesion kinase signaling pathways.
2008
A comparative biochemical and structural analysis of the intracellular chorismate mutase (Rv0948c) from Mycobacterium tuberculosis H(37)R(v) and the secreted chorismate mutase (y2828) from Yersinia pestis.
2006
Biochemical and structural characterization of the secreted chorismate mutase (Rv1885c) from Mycobacterium tuberculosis H37Rv: an *AroQ enzyme not regulated by the aromatic amino acids.