Molecular biology in nutrition research: modeling of folate metabolism.

Model CHO cells obtained by transfecting CHO mutants with the E. coli and human folylpolyglutamate synthetase genes have proven useful for assessing the role of folylpolyglutamates in one carbon metabolism and for delineating how folate intracellular stores are regulated. Cells expressing enzymes in specific subcellular compartments, expressing enzymes with different substrate specificity's, and expressing enzyme activity at different levels, all in a common background, in this case the CHO cell, has allowed the development of kinetic models for assessing the role of folypolyglutamate synthetase in folate retention and in the cytotoxicity of antifolates.