Van Schaftingen et al (JIMD, pub on line Jan 8, 2013) recently wrote a very interesting short review discussing several enzymes whose sole purpose appears to be to process aberrantly produced metabolites. These abnormal metabolites, such as L-2-hydroxyglutarate, are the product of substrate non-specificity of certain enzymes. This group proposes that defects in as of yet unknown “proofreading” enzymes could be responsible for human disease.
It is fascinating that the sole purpose of these proofreading enzymes is to clean up the byproducts of human metabolism, and speaks to the not- yet- fully- appreciated complexity of these integrated metabolic pathways.
Hilary Vernon, MD PhD