The molybdenum cofactor (Moco) is a remarkable metal center that lies at the catalytic heart of a variety of enzymes. The unique and `universal'Moco has the same core structure in all mononuclear molybdenum enzymes (MMEs) and is found in all forms of life. The ability of this cofactor to mediate oxygen atom transfer (OAT) and hydroxylation reactions, has given rise to the diverse family of MMEs. Similarly constituted, MMEs include dehydrogenases (e.g., formate, ethylbenzene), oxidases (e.g., sulfide, xanthine, arsenite), and reductases (e.g., nitrate, arsenate, selenate). In humans, xanthine oxidase and sulfite oxidase fulfill crucial functions in redox reactions in sulfur and purine metabolism. Microbial MMEs also indirectly impact human health through transformation of nitrate and arsenic. Defects in cofactor synthesis can result in severe physiological abnormalities leading to death. A fundamental question in biology and medicine is how has the basic unit of Moco been tuned to fulfill the various functions. The ultimate goal of our research is to better understand the reactivity of MMEs through an integrated program of inorganic, organic, physical, and reactivity studies. The broad questions that we are interested in answering are: What controls the reactivity in MMEs? How does the physical structure impose electronic structures that support the same substrate transformation with different active sites? How do these active sites influence the different phases of the catalytic cycle i.e., substrate binding, product formation, product releases and regeneration of the active site? These questions will be addressed by investigating the OAT reactivity and redox properties of molybdenum complexes and examining influence imposed by individual components of the cofactor. We will also synthesize and fully characterize oxo molybdenum complexes of dithione ligands, and investigate their properties. In addition, we conduct transmetallation reaction from copper to molybdenum, and complete the synthesis of the closest analog of pyranopterin cofactor. In accordance with the guideline of R15 program we will continue to train next generation of scientists. This proposal seeks to address fundamental questions relating to a class of enzymes that are important to human health though a hypothesis driven research.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Academic Research Enhancement Awards (AREA) (R15)
Project #
3R15GM061555-03A1S1
Application #
7921704
Study Section
Macromolecular Structure and Function A Study Section (MSFA)
Program Officer
Anderson, Vernon
Project Start
2009-09-15
Project End
2011-03-31
Budget Start
2009-09-15
Budget End
2011-03-31
Support Year
3
Fiscal Year
2009
Total Cost
$36,580
Indirect Cost
Name
Duquesne University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
004501193
City
Pittsburgh
State
PA
Country
United States
Zip Code
15282
Ratvasky, Stephen C; Mogesa, Benjamin; van Stipdonk, Michael J et al. (2016) A mixed valence zinc dithiolene system with spectator metal and reactor ligands. Polyhedron 114:370-377
Yang, Jing; Mogesa, Benjamin; Basu, Partha et al. (2016) Large Ligand Folding Distortion in an Oxomolybdenum Donor-Acceptor Complex. Inorg Chem 55:785-93
Mogesa, Benjamin; Perera, Eranda; Rhoda, Hannah M et al. (2015) Solution, Solid, and Gas Phase Studies on a Nickel Dithiolene System: Spectator Metal and Reactor Ligand. Inorg Chem 54:7703-16
Basu, Partha; Burgmayer, Sharon J Nieter (2015) Recent developments in the study of molybdoenzyme models. J Biol Inorg Chem 20:373-83
Sparacino-Watkins, Courtney; Stolz, John F; Basu, Partha (2014) Nitrate and periplasmic nitrate reductases. Chem Soc Rev 43:676-706
Pimkov, Igor V; Peterson, Antoinette; Vaccarello, David N et al. (2014) A Regioselective Synthesis of the Dephospho DIthiolene Protected Molybdopterin. RSC Adv 4:19072-19076
van Stipdonk, Michael J; Basu, Partha; Dille, Sara A et al. (2014) Infrared multiple photon dissociation spectroscopy of a gas-phase oxo-molybdenum complex with 1,2-dithiolene ligands. J Phys Chem A 118:5407-18
Hille, Russ; Hall, James; Basu, Partha (2014) The mononuclear molybdenum enzymes. Chem Rev 114:3963-4038
Pimkov, Igor V; Nigam, Archana; Venna, Kiran et al. (2013) Dithiolopyranthione Synthesis, Spectroscopy and an Unusual Reactivity with DDQ. J Heterocycl Chem 50:879-886
Deibler, Kristine; Basu, Partha (2013) Continuing issues with Lead: Recent Advances in Detection. Eur J Inorg Chem 2013:1086-1096

Showing the most recent 10 out of 27 publications