Identification of the mammalian DNA-binding protein P8 as glyceraldehyde-3-phosphate dehydrogenase.
The DNA-binding protein P8 from transformed hamster fibroblasts (line NIL-1-hamster sarcoma virus) has been purified to homogeneity by DNA-cellulose and phosphocellulose chromatography. The molecular weight of dissociated P8 is 36000, the same as that reported for the subunits of glyceraldehyde-3-phosphate dehydrogenase, and the mobility of these proteins in polyacrylamide gels is identical. The amino acid composition of P8 is very similar to that of glyceraldehyde-3-phosphate dehydrogenase. When assayed for glyceraldehyde-3-phosphate dehydrogenase activity the P8 preparation had a specific activity of 54.6 units/mg, a value comparable to that of the crystalline enzyme from several sources. Furthermore, serum prepared against P8 crossreacts with glyceraldehyde-3-phosphate dehydrogenase from hamster muscle. These results show that P8 is glyceraldehyde-3-phosphate dehydrogenase. The interaction of P8 from transformed fibroblasts and glyceraldehyde-3-phosphate dehydrogenase from hamster and rabbit muscle with DNA has been studied using a Millipore filtration technique. These proteins have affinity for single-stranded DNA but not for double-stranded DNA.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002460:Cell Line; D002472:Cell Transformation, Viral; D004247:DNA; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D005779:Immunodiffusion; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology; D011485:Protein Binding; D011506:Proteins; D012190:Retroviridae; D013552:Swine
D000596:Amino Acids; D011506:Proteins; D004247:DNA; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases