skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Tyrosine Aminotransferase: Biochemical and Structural Properties and Molecular Dynamics Simulations

Abstract

Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine and other aromatic amino acids. The enzyme is thought to play a role in tyrosinemia type II, hepatitis and hepatic carcinoma recovery. The objective of this study is to investigate its biochemical and structural characteristics and substrate specificity in order to provide insight regarding its involvement in these diseases. Mouse TAT (mTAT) was cloned from a mouse cDNA library, and its recombinant protein was produced using Escherichia coli cells and purified using various chromatographic techniques. The recombinant mTAT is able to catalyze the transamination of tyrosine using {alpha}-ketoglutaric acid as an amino group acceptor at neutral pH. The enzyme also can use glutamate and phenylalanine as amino group donors and p-hydroxy-phenylpyruvate, phenylpyruvate and alpha-ketocaproic acid as amino group acceptors. Through macromolecular crystallography we have determined the mTAT crystal structure at 2.9 {angstrom} resolution. The crystal structure revealed the interaction between the pyridoxal-5'-phosphate cofactor and the enzyme, as well as the formation of a disulphide bond. The detection of disulphide bond provides some rational explanation regarding previously observed TAT inactivation under oxidative conditions and reactivation of the inactive TAT in the presence of a reducing agent. Molecular dynamics simulations using the crystal structuresmore » of Trypanosoma cruzi TAT and human TAT provided further insight regarding the substrate-enzyme interactions and substrate specificity. The biochemical and structural properties of TAT and the binding of its cofactor and the substrate may help in elucidation of the mechanism of TAT inhibition and activation.« less

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE SC OFFICE OF SCIENCE (SC)
OSTI Identifier:
1042288
Report Number(s):
BNL-97966-2012-JA
TRN: US201212%%699
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Journal Article
Journal Name:
Protein and Cell
Additional Journal Information:
Journal Volume: 1; Journal Issue: 11
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 60 APPLIED LIFE SCIENCES; AMINO ACIDS; AMINOTRANSFERASES; AROMATICS; CARCINOMAS; CRYSTAL STRUCTURE; CRYSTALLOGRAPHY; DETECTION; DISEASES; DYNAMICS; ENZYMES; ESCHERICHIA COLI; HEPATITIS; HUMAN POPULATIONS; INACTIVATION; INHIBITION; INTERACTIONS; MOLECULAR DYNAMICS METHOD; PHENYLALANINE; PROTEINS; REDUCING AGENTS; RESOLUTION; SPECIFICITY; SIMULATION; SUBSTRATES; TRYPANOSOMA; TYROSINE

Citation Formats

Mehere, P, Han, Q, Lemkul, J, Vavricka, C, Robinson, H, Bevan, D, and Li, J. Tyrosine Aminotransferase: Biochemical and Structural Properties and Molecular Dynamics Simulations. United States: N. p., 2011. Web.
Mehere, P, Han, Q, Lemkul, J, Vavricka, C, Robinson, H, Bevan, D, & Li, J. Tyrosine Aminotransferase: Biochemical and Structural Properties and Molecular Dynamics Simulations. United States.
Mehere, P, Han, Q, Lemkul, J, Vavricka, C, Robinson, H, Bevan, D, and Li, J. 2011. "Tyrosine Aminotransferase: Biochemical and Structural Properties and Molecular Dynamics Simulations". United States.
@article{osti_1042288,
title = {Tyrosine Aminotransferase: Biochemical and Structural Properties and Molecular Dynamics Simulations},
author = {Mehere, P and Han, Q and Lemkul, J and Vavricka, C and Robinson, H and Bevan, D and Li, J},
abstractNote = {Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine and other aromatic amino acids. The enzyme is thought to play a role in tyrosinemia type II, hepatitis and hepatic carcinoma recovery. The objective of this study is to investigate its biochemical and structural characteristics and substrate specificity in order to provide insight regarding its involvement in these diseases. Mouse TAT (mTAT) was cloned from a mouse cDNA library, and its recombinant protein was produced using Escherichia coli cells and purified using various chromatographic techniques. The recombinant mTAT is able to catalyze the transamination of tyrosine using {alpha}-ketoglutaric acid as an amino group acceptor at neutral pH. The enzyme also can use glutamate and phenylalanine as amino group donors and p-hydroxy-phenylpyruvate, phenylpyruvate and alpha-ketocaproic acid as amino group acceptors. Through macromolecular crystallography we have determined the mTAT crystal structure at 2.9 {angstrom} resolution. The crystal structure revealed the interaction between the pyridoxal-5'-phosphate cofactor and the enzyme, as well as the formation of a disulphide bond. The detection of disulphide bond provides some rational explanation regarding previously observed TAT inactivation under oxidative conditions and reactivation of the inactive TAT in the presence of a reducing agent. Molecular dynamics simulations using the crystal structures of Trypanosoma cruzi TAT and human TAT provided further insight regarding the substrate-enzyme interactions and substrate specificity. The biochemical and structural properties of TAT and the binding of its cofactor and the substrate may help in elucidation of the mechanism of TAT inhibition and activation.},
doi = {},
url = {https://www.osti.gov/biblio/1042288}, journal = {Protein and Cell},
number = 11,
volume = 1,
place = {United States},
year = {Sat Dec 31 00:00:00 EST 2011},
month = {Sat Dec 31 00:00:00 EST 2011}
}