Abstract
The synthesis of a new inhibitor, N-phosphonacetyl-L-isoasparagine (PALI), of Escherichia coli aspartate transcarbamoylase (ATCase) is reported, as well as structural studies of the enzyme.PALI complex. PALI was synthesized in 7 steps from beta-benzyl L-aspartate. The KD of PALI was 2 microM. Kinetics and small-angle X-ray scattering experiments showed that PALI can induce the cooperative transition of ATCase from the T to the R state. The X-ray structure of the enzyme.PALI complex showed 22 hydrogen-bonding interactions between the enzyme and PALI. The kinetic characterization and crystal structure of the ATCase.PALI complex also provides detailed information regarding the importance of the alpha-carboxylate for the binding of the substrate aspartate.
Publication types
-
Research Support, N.I.H., Extramural
-
Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
-
Asparagine / analogs & derivatives*
-
Asparagine / chemical synthesis
-
Asparagine / chemistry
-
Aspartate Carbamoyltransferase / antagonists & inhibitors*
-
Aspartate Carbamoyltransferase / chemistry*
-
Aspartic Acid / analogs & derivatives
-
Aspartic Acid / chemistry
-
Binding Sites
-
Crystallography, X-Ray
-
Escherichia coli / enzymology*
-
Hydrogen Bonding
-
Kinetics
-
Models, Molecular
-
Molecular Structure
-
Organophosphonates / chemical synthesis*
-
Organophosphonates / chemistry
-
Phosphonoacetic Acid / analogs & derivatives
-
Phosphonoacetic Acid / chemistry
Substances
-
N-phoshponacetylisoasparagine
-
Organophosphonates
-
Aspartic Acid
-
Asparagine
-
sparfosic acid
-
Aspartate Carbamoyltransferase
-
Phosphonoacetic Acid