Platelet-derived endothelial cell growth factor has thymidine phosphorylase activity.
Platelet-derived endothelial cell growth factor (PD-ECGF), a protein which stimulates angiogenesis in vivo, is shown to have a 39.2% amino acid sequence similarity over a 439 amino acid region with the thymidine phosphorylase of Escherichia coli (E. coli). Using recombinant human PD-ECGF, we show that PD-ECGF has thymidine phosphorylase activity. Analysis by gel chromatography revealed that recombinant human PD-ECGF occurs as a 90 kDa homodimer, similar to other thymidine phosphorylases. In addition to a possible effect on DNA synthesis, PD-ECGF was shown to affect [3H]thymidine assays in a manner which is not related to cell proliferation. The in vitro and in vivo effects of PD-ECGF may thus occur by an indirect mechanism through its enzymatic activity.
Usuki
K
K
Ludwig Institute for Cancer Research, Biomedical Center, Uppsala, Sweden.
Saras
J
J
Waltenberger
J
J
Miyazono
K
K
Pierce
G
G
Thomason
A
A
Heldin
C H
CH
D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D002850:Chromatography, Gel; D004730:Endothelium, Vascular / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology; D005798:Genes, Bacterial; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D013552:Swine; D013936:Thymidine / Q000378:metabolism; D013939:Thymidine Phosphorylase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
D011994:Recombinant Proteins; D013939:Thymidine Phosphorylase; D013936:Thymidine