[Using of 4-thiouridine and 4-thiothymidine for pyrimidine nucleoside phosphorylase studing].
4-Thiouridine and 4-thiothymidine were developed as efficient substrates for spectrophotometric determination of uridine phosphorylase and thymidine phosphorylase activity. 4-Thiouridine has maximum absorbance at 330 nm (pH 7.5). The change in extinction coefficient for 4-thiouridine/4-thiouracil, deltaepsilon is 3000 M(-1) x cm(-1). It appeared that 4-thiouridine is a good substrate for uridine phosphorylase with Michaelis-Menten constant 130 microM and kcat 49 s(-1). In the case of 4-thiothymidine/4-thiothymine deltaepsilon is even larger: 5000 M(-1) x cm(-1) at 336 nm.
Panova
N G
NG
Shcheveleva
E V
EV
Alekseev
K S
KS
Mukhortov
V G
VG
Zuev
A N
AN
Mikhaĭlov
S N
SN
Esipov
R S
RS
Chuvikovskiĭ
D V
DV
Miroshnikov
A I
AI
D009682:Magnetic Resonance Spectroscopy; D010430:Pentosyltransferases / Q000737:chemistry / Q000378:metabolism*; D057845:Pyrimidine Phosphorylases; D013053:Spectrophotometry; D013379:Substrate Specificity; D013891:Thiouridine / Q000737:chemistry* / Q000378:metabolism; D013936:Thymidine / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism
C414668:4-thiothymidine; D013891:Thiouridine; D010430:Pentosyltransferases; D057845:Pyrimidine Phosphorylases; D013936:Thymidine