Design and evaluation of 5'-modified nucleoside analogs as prodrugs for an E. coli purine nucleoside phosphorylase mutant.
Our studies have led to the identification of an E. coli PNP mutant (M64V) that is able to cleave numerous 5'-modified nucleoside analogs with much greater efficiency than the wild-type enzyme. The biological activity of the three best substrates of this mutant (9-[6-deoxy-alpha-L-talofuranosyl]-6-methylpurine (methyl(talo)-MeP-R), 9-[6-deoxy-alpha-L-talofuranosyl]-2-F-adenine, and 9-[alpha-L-lyxofuranosyl]-2-F-adenine) were evaluated so that we can optimally utilize these compounds. Our results indicated that the mechanism of toxicity of methyl(talo)-MeP-R to mice was due to its cleavage to MeP by a bacterial enzyme, and that the toxicity of the two F-Ade analogs was due to their cleavage to F-Ade by mammalian methylthioadenosine phosphorylase.
Parker
William B
WB
Southern Research Institute, 2000 Ninth Ave., South, Birmingham, AL 35205, USA. parker@sri.org
Allan
Paula W
PW
Ealick
Steve E
SE
Sorscher
Eric J
EJ
Hassan
Abdalla E A
AE
Silamkoti
A V
AV
Fowler
Anita T
AT
Waud
William R
WR
Secrist
John A
JA
D000818:Animals; D002460:Cell Line; D045744:Cell Line, Tumor; D002626:Chemistry, Pharmaceutical / Q000379:methods; D015195:Drug Design; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D020128:Inhibitory Concentration 50; D051379:Mice; D008956:Models, Chemical; D009154:Mutation; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D011355:Prodrugs / Q000138:chemical synthesis / Q000494:pharmacology*; D011683:Purine-Nucleoside Phosphorylase / Q000235:genetics* / Q000378:metabolism*; D013379:Substrate Specificity; D013872:Thionucleosides / Q000737:chemistry
D009705:Nucleosides; D011355:Prodrugs; D013872:Thionucleosides; D011683:Purine-Nucleoside Phosphorylase; C021784:5'-methylthioadenosine phosphorylase