S]thioate analogue of UDP-Glc is efficiently utilized by the glucose phosphotransferase and is relatively resistant to hydrolytic degradation
The β-phosphoro[35S]thioate analogue of UDP-glucose ((β-35S)UDP-Glc) is utilized with approximately the same efficiency as the parent compound by the UDP-glucose:glycoprotein glucose-1-phosphotransferase (glucosyltransferase), which catalyzes the transfer of αGlc-1-P from UDP-Glc to mannose-containing oligosaccharides on acceptor glycoproteins. The same endogenous acceptor glycoproteins are labeled by the glucosyltransferase using [β-32P]UDP-Glc and (β-35S)UDP-Glc. However, in liver homogenates, incorporation from [β-32P]UDP-Glc ceases to increases after about 4 min of incubation, while incorporation from (β-35S)UDP-Glc persists for at least 1 h. This difference is due to an approx. 10-fold slower hydrolytic rate for the phosphorothioate analogue than for the parent compound, a finding similar to previous work showing that a variety of nucleases and phosphodiesterases are less efficient in cleaving phosphorothioate DNA than the native polymer. © 1987.
Marchase, RB; Saunders, AM; Rivera, AA; Cook, JM
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