Structure-based drug design of selective 5'-nucleotidases inhibitors
Petr Pachl1, Jiří Brynda1,2, Ivan Rosenberg 2,
Milan Fábry1, Pavlína Řezáčová1,2
1Institute
of Molecular Genetics, Flemingovo nam. 2, Prague 6, Prague, 16610, Czech
Republic, 2Institute of Organic Chemistry and Biochemistry AS CR,
Flemingovo nam. 2, Prague 6, Prague, 16610, Czech Republic
The monophosphate 5'-nucleotidases, including 5'(3')-deoxyribonucleotidase,
belong to a family of enzymes that catalyze the dephosphorylation of nucleoside
monophosphates. The ribonucleotides and deoxyribonucleotides can be synthesized
de novo from low-molecular-weight
precursors or by salvage from nucleosides or nucleobases produced in catabolism
of nucleic acids[1]. In this salvage pathway, ribonucleotides and
deoxyribonucleotides are phosphorylated by nucleoside and nucleotide kinases to
maintain sufficient pools of dNTP's and NTP's for synthesis of DNA and RNA,
respectively. The phosphorylation by cellular nucleoside kinases is opposed by
5'-nucleotidases that dephosphorylate ribo- and deoxyribonucleoside
monophosphates[2,3,4]. Besides their role in the regulation of physiological
dNTP pools, substrate cycles between ribonucleotidases and kinases may affect
the therapeutic action of pyrimidine nucleoside analogs used as anticancer and
antiviral agents. Such compounds require the nucleoside kinases activity for
phosphorylation to their active forms. Results of clinical and in vitro studies propose that an
increase in nucleotidase activity can interfere with nucleoside analogue
activation resulting in drug resistance[5].
The main goal of this project is the search
for potent and selective inhibitors of mammalian 5'-nucleotidases based on
nucleoside phosphonic acids and their derivatives and comparison of sensitivity
of 5'-nucleotidases isolated from various sources toward individual inhibitors.
We
have prepared 2 types of human 5'-nucleotidase: cytosolic and mitochondrial by
recombinant expression in E. coli. Two strategies of finding potential inhibitors
are used. First, a random series of nucleoside phosphonic acids derivatives are
tested. Second, testing of rationally designed
compounds based on a published
structure of known inhibitor-enzyme complex[6]. In this structure-based design
we have already found 100x better inhibitor of mitochondrial nucleotidase and
some other promising compounds.
In general, compounds of strong and
selective inhibitory potency are of high medicinal interest as antimetabolites
for anticancer and antiviral therapy.
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characterization of six unrelated Italian patients affected by pyrimidine
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