TY - JOUR
T1 - Heterologous expression of xenobiotic mammalian-metabolizing enzymes in mutagenicity tester bacteria
T2 - An update and practical considerations
AU - Kranendonk, Michel
AU - Laires, António
AU - Rueff, José
AU - Estabrook, Ronald W.
AU - Vermeulen, Nico P.E.
PY - 2000
Y1 - 2000
N2 - There is an increasing need for metabolic competent cell systems for the mechanistic studies of biotransformation of xenobiotics in toxicology in general and in genotoxicology in particular. These cell systems combine the heterologous expression of a particular mammalian biotransformation enzyme with a specific target/end point by which a functional analysis of the expressed gene product in the (geno)toxicity of chemicals can be performed, cDNAs of an increasing number of mammalian biotransformation enzymes is being cloned. The construction of specific expression vectors permits their heterologous expression in laboratory bacteria, such as Escherichia coli strains. This development does not only allow biochemical and enzymatic studies of (pure) enzyme preparations but also facilitates the engineering of metabolically competent mutagenicity tester bacteria; thereby providing new tools for genotoxicity testing and for studying of the roles of biotransformation in chemical carcinogenesis. In this review, we describe an update as well as an evaluation of enzymes expressed in mutagenicity tester bacteria. Four types of biotransformation enzymes are now expressed in these bacteria, namely, GSTs, CYPs, NATs, and STs. The expression of these enzymes in the tester bacteria and their subsequent application in mutagenicity assays demonstrates that heterologous expression in this type of bacteria has a number implications for the functionality of the biotransformation enzymes as well as for the functioning of the tester bacteria in mutagenicity detection. We also describe here a number of practical considerations in this regard.
AB - There is an increasing need for metabolic competent cell systems for the mechanistic studies of biotransformation of xenobiotics in toxicology in general and in genotoxicology in particular. These cell systems combine the heterologous expression of a particular mammalian biotransformation enzyme with a specific target/end point by which a functional analysis of the expressed gene product in the (geno)toxicity of chemicals can be performed, cDNAs of an increasing number of mammalian biotransformation enzymes is being cloned. The construction of specific expression vectors permits their heterologous expression in laboratory bacteria, such as Escherichia coli strains. This development does not only allow biochemical and enzymatic studies of (pure) enzyme preparations but also facilitates the engineering of metabolically competent mutagenicity tester bacteria; thereby providing new tools for genotoxicity testing and for studying of the roles of biotransformation in chemical carcinogenesis. In this review, we describe an update as well as an evaluation of enzymes expressed in mutagenicity tester bacteria. Four types of biotransformation enzymes are now expressed in these bacteria, namely, GSTs, CYPs, NATs, and STs. The expression of these enzymes in the tester bacteria and their subsequent application in mutagenicity assays demonstrates that heterologous expression in this type of bacteria has a number implications for the functionality of the biotransformation enzymes as well as for the functioning of the tester bacteria in mutagenicity detection. We also describe here a number of practical considerations in this regard.
KW - Bioactivation
KW - Biotransformation
KW - E. coli
KW - Heterologous expression
KW - Mutagenicity
KW - S. typhimurium
UR - http://www.scopus.com/inward/record.url?scp=0034080524&partnerID=8YFLogxK
U2 - 10.1080/10408440091159211
DO - 10.1080/10408440091159211
M3 - Review article
C2 - 10852498
AN - SCOPUS:0034080524
SN - 1040-8444
VL - 30
SP - 287
EP - 306
JO - Critical Reviews In Toxicology
JF - Critical Reviews In Toxicology
IS - 3
ER -