The long term goal of this project is to understand the structural basis of substrate recognition and catalytic mechanism for a group of acyltransferases. Based on sequence homology and reaction mechanism, these acyltransferases constitute a unique gene family which serve crucial physiological roles. For instance, carnitine palmitoylransferase I and II are essential for b-oxidation of long chain fatty acids in mitochondria and are responsible for excessive rates of fatty acid oxidation in pathological states such as diabetes and ketosis. Choline acetyltransferase is responsible for the biosynthesis of the neurotransmitter acetylcholine; a deficiency in the enzymatic activity has been correlated with the loss of cognitive functions in Alzheimer's disease. The other acetyltransferase of this family, carnitine acetyltransferase, plays an important role in the maintenance of mitochondrial CoASH/acetylCoA balance, cellular energy metabolism, detoxification and cell cycle regulation. Acetylcarnitine was reported to protect neuronal cell loss in ischemia and improve cognitive functions in Alzheimer's disease patients. A deficiency or acetylcarnitine in sera of a group of AIDS patients was recently reported in a severe dose-limiting axonal peripheral neuropathy caused by several antiretroviral agents such as ddl, ddC and d4T. Therefore, molecular analysis of these acyltransferases is of significance to our understanding of the mechanisms of enzyme action as well as the mechanisms involved in pathological conditions. In this proposal, we will focus on the structure/function/regulatory relationship of these acyltransferases. Specifically, we propose to determine the structural basis of substrate recognition of these acyltransferases using a combination of biophysical and molecular genetic approaches.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
7R01GM058197-02
Application #
6021627
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1998-09-01
Project End
2001-08-31
Budget Start
1998-11-01
Budget End
1999-08-31
Support Year
2
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Florida
Department
Pharmacology
Type
Schools of Pharmacy
DUNS #
073130411
City
Gainesville
State
FL
Country
United States
Zip Code
32611
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Qhobosheane, Monde; Liu, Xiaojing; Gu, Yunrong et al. (2003) Two-dimensional imaging biosensor for the monitoring of lactate released from brain slices. Appl Spectrosc 57:689-96
Wu, Donghai; Govindasamy, Lakshmanan; Lian, Wei et al. (2003) Structure of human carnitine acetyltransferase. Molecular basis for fatty acyl transfer. J Biol Chem 278:13159-65
Lian, Wei; Govindasamy, Lakshmanan; Gu, Yunrong et al. (2002) Crystallization and preliminary X-ray crystallographic studies on recombinant human carnitine acetyltransferase. Acta Crystallogr D Biol Crystallogr 58:1193-4