title: Origin of the triosephosphate isomerase isozymes in humans: genetic evidence for the expression of a single structural locus.
abstract: A genetic approach is used to ascertain that a single structural locus for triosephosphate isomerase (TPI) (E.C.5.3.1.1.) is expressed in rapidly dividing human lymphoblasts. This approach is made possible through the identification of a rare electrophoretic variant of human TPI. The variant phenotype is expressed by the TPI-B isozyme in both erythrocytes and peripheral lymphocytes. The variant phenotype is also expressed in the thermostability and electrophoretic pattern of the TPI-A isozyme in mitogen-stimulated lymphoblasts, indicating that TPI-A and TPI-B are products of the same structural locus. These findings are in contrast to the recent conclusions of Yuan et al. based upon structural analysis, suggesting that the TPI-A and TPI-B isozymes are products of distinct structural loci.
mesh_terms: D002238:Carbohydrate Epimerases / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D005796:Genes; D014644:Genetic Variation; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D007700:Kinetics; D008214:Lymphocytes / Q000201:enzymology; D010641:Phenotype; D014305:Triose-Phosphate Isomerase / Q000097:blood / Q000235:genetics*
chemical_list: D007527:Isoenzymes; D002238:Carbohydrate Epimerases; D014305:Triose-Phosphate Isomerase