David A. Okar

Current Position (s): Assistant Professor/Research Associate

Research Interests and areas of potential collaboration:
Main research interest is structure and function of proteins and enzymes related to carbohydrate metabolism, especially in the liver.

1. Use of NMR spectroscopy to determine the reaction mechanism of fructose-2,6-bisphosphatase.

2. Determination of the solution structure of the fructose-2,6-bisphosphatase domain by NMR.

3. Investigation of the mechanism by which phosphorylation of Ser-32 in 6-phosphofructo-2-kinase/Fructose-2,6-bisphosphatase controls the kinase and bisphosphatase activities.Selected publications:

Okar, DA, Kakalis, LT, Narula, SS, Armitage, I.M, Pilkis, SJ., Biochem. J., 308, 189-195, (1995). "Identification of trasient intermediates in the bisphosphatase reaction of rat liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase by 31P NMR spectroscopy".

Okar, DA, Felicia, ND, Gui, L, Lange, AJ, Protein Express. and Purif., 11(1), 79-85, (1997).   "Labeling of Recombinant Protein for NMR Spectroscopy: Global and Specific Labeling of the Rat Liver Fructose 2,6-Bisphosphatase Domain".

Okar, DA, Lee, YH, Argaud, D, McFarlan, SC, Lange, AJ, Frontiers in Diabetes, Vol. 14, S. Karger AG, Basel (eds.  Belfiore. F, Lorenzi, M, Molinatti, GM, Porta, M.) 30-46, (1998).  "The 6-Phospho-2-Kinase/Fructose-2,6-Bisphosphatase System: Regulation by Insulin and an Insulinomimetic Approach to Lowering Blood Glucose Levels".

Okar, DA, Lange, AJ, Biofactors, 10, 1-14, (1999). "Fructose-2,6-bisphosphate and Control of Carbohydrate Metabolism in Eukaryotes".

Okar, DA, Live, DH, Kirby, TL, Karschnia, EJ, von Weymarn, LB, Armitage, IM, Lange, AJ, Biochemistry, 38(14), 4471-4479, (1999).  "The Roles of Glu-327 and His-446 in the Bisphosphatase Reaction of Rat Liver 6-Phosphofructo-2-kinase/ Fructose-2,6-bisphosphatase Probed by NMR Spectroscopic and Mutational Analyses of the Enzyme in the Transient Phosphohistidine Intermediate Complex".

Okar, DA, Live, DH, Devany, MH, Lange, AJ, "The Mechanism of the Bisphosphatase Reaction of 6-Phosphofructo-2-kinase/Fructose-2,6-bisphosphatase Probed by 1H - 15N NMR Spectroscopy". Biochemistry,  2000.