Associate Professor

Joined the faculty: 1990

Affiliations:

Teaching: BIOC 339, MS1 PBL, CCMD 730, HSTA, BIOC 693
 
Office: 3103B
Phone: (304) 293-2310
Fax: (304) 293-6846
Email: ashiemke@hsc.wvu.edu

The main focus of research in this laboratory is the structural and mechanistic characterization of metal-containing enzymes and proteins. Many protein active sites contain one or more of the transition elements (Fe, Cu,, Mn, etc.) making them amenable to investigation using Spectroscopic techniques specific for the metal center. Electron Paramagnetic Resonance (EPR), resonance Raman, and X-ray Absorption spectroscopies are used to probe the structure of the metal center, from which the detailed mechanism of the enzyme may be deduced. Of particular interest is the role played by transition metals in bacterial oxygen activation and hydrocarbon metabolism. One enzyme currently under study is methane monooxygenase (MMO) from methanotrophic bacteria. These bacteria obtain energy and carbon from the aerobic oxidation of methane. MMO initiates this process via catalysis of the oxidation of methane by 02 , producing methanol and water. Though this reaction is similar to those catalyzed by other mixed-function oxidases, MMO is the only enzyme known to oxidize small (less than 4 carbon), straight-chain alkanes. Recent studies have shown that copper is required for activity. Future work is aimed at elucidating the structural and mechanistic features which give this enzyme its unique alkane oxidizing properties. Of particular interest is the role played by copper or other transition metals present at the site of dioxygen binding and alkane hydroxylation.

  References:

• “Inhibition of membrane-bound methane monooxygenase and ammonia monooxygenase by diphenyliodonium: implications for electron transfer” Andrew K. Shiemke, Daniel J. Arp, and Sayavedra-Soto LA. J. Bacteriol. 2004, 186, 928-937.
   
• “Evidence that a type-2 NADH:quinone oxidoreductase mediates electron transfer to particulate methane monooxygenase in methylococcus capsulatus” Scott A. Cook and Andrew K. Shiemke, Arch. Biochem. Biophys. 2002, 398, 32-40.
   
• "Detergent Solubilization of Membrane-Bound Methane Monooxygenase Requires Plastoquinol Analogs as Electron Donors" Andrew K. Shiemke, Scott A. Cook, Tim Miley , and Patrick Singlton Arch. Biochem. Biophys. 1995, 321, 421-428.
   
• "Evidence that Cooper is a Required Cofactor for the Membrane-Bound Form of Methane Monooxygenase" Scott A. Cook and Andrew K. Shiemke, J. Inorg. Biochem, 1995, In Press.
   
• "Cytochrome aa3 From Methylococcus capsulatus (Bath)" Alan A. DiSpirito, Andrew K. Shiemke, S.W. Jordan, James A. Zahn, and Cinder L. Krema; Arch. Microbiol., 1994, 161, 258-265.
   
• "The Nature of the Copper Ions in the Membranes Containing the Particulate Methane Monooxygenase from Methylococcus capsulatus (Bath)" Hoa T. Nguyen, Andrew K. Shiemke, S. Joshua Jacobs, Brian J. Hales, Mary E. Lidstrom, and Sunney I. Chan; J.Biol. Chem. 1994, 269, 14995-15005.
   
• "In Situ Bioremediation of Chlorinated Aliphatic Hydrocarbons in Soil and Groundwater" Joan Cuddeback, William A. Sack, Patrick E. Carriere, Andrew K. Shiemke, and Chad Whiteman, Hazardous and Industrial Wastes, Proceedings of the 26th Mid-Atlantic Industrial Waste Conference, C.P. Huang, Ed., pp. 131-140, Technomic Publishing Co., 1994.