K. Miyadera et al., STRUCTURAL CHARACTERIZATION OF THYMIDINE PHOSPHORYLASE PURIFIED FROM HUMAN PLACENTA, Biochemical and biophysical research communications, 212(3), 1995, pp. 1040-1045
Human thymidine phosphorylase (dThdPase) is thought to be identical to
an angiogenesis factor, platelet-derived endothelial cell growth fact
or (PD-ECGF). However, the whole amino acid sequence of dThdPase is st
ill unknown. N-terminal amino acid sequencing of dThdPase isolated fro
m human placenta gave the sequence Ac-AALMTPGTGAPPAPG. Comparison with
the sequence predicted from the PD-ECGF cDNA reveals that residues 21
6 of dThdPase are identical to that of PD-ECGF. If dThdPase and PD-ECG
F are derived from the same gene, the primary translational product of
dThdPase would be processed one amino acid from the translation-initi
ating methionine residue and Ala-2 acetylated. Since placental and pla
telet PD-ECGF is reported to be processed at Thr-6 and Ala-11, respect
ively, and the N-terminal end is not blocked, further study is needed
to clarify the reason for this discrepancy and whether the difference
in N-terminal sequence affects the physiological function of these mol
ecules. (C) 1995 Academic Press, Inc.