TY - JOUR
T1 - Transition state analogue inhibitors of purine nucleoside phosphorylase from Plasmodium falciparum
AU - Kicska, Gregory A.
AU - Tyler, Peter C.
AU - Evans, Gary B.
AU - Furneaux, Richard H.
AU - Kim, Kami
AU - Schramm, Vern L.
PY - 2002/2/1
Y1 - 2002/2/1
N2 - Immucillins are logically designed transition-state analogue inhibitors of mammalian purine nucleoside phosphorylase (PNP) that induce purine-less death of Plasmodium falciparum in cultured erythrocytes (Kicska, G. A., Tyler, P. C., Evans, G. B., Furneaux, R. H., Schramm, V. L., and Kim, K. (2002) J. Biol. Chem. 277, 3226-3231). PNP is present at high levels in human erythrocytes and in P. falciparum, but the Plasmodium enzyme has not been characterized. A search of the P. falciparum genome data base yielded an open reading frame similar to the PNP from Escherichia coli. PNP from P. falciparum (P. falciparum PNP) was cloned, overexpressed in E. coli, purified, and characterized. The primary amino acid sequence has 26% identity with E. coli PNP, has 20% identity with human PNP, and is phylogenetically unique among known PNPs with equal genetic distance between PNPs and uridine phosphorylases. Recombinant P. falciparum PNP is catalytically active for inosine and guanosine but is less active for uridine. The immucillins are powerful inhibitors of P. falciparum PNP. Immucillin-H is a slow onset tight binding inhibitor with a Kii* value of 0.6 nM. Eight related immucillins are also powerful inhibitors with dissociation constants from 0.9 to 20 nM. The Km/Ki* value for immucillin-H is 9000, making this inhibitor the most powerful yet reported for P. falciparum PNP. The PNP from P. falciparum differs from the human enzyme by a lower Km for inosine, decreased preference for deoxyguanosine, and reduced affinity for the immucillins, with the exception of 5′-deoxy-immucillin-H. These properties of P. falciparum PNP are consistent with a metabolic role in purine salvage and provide an explanation for the antibiotic effect of the immucillins on P. falciparum cultured in human erythrocytes.
AB - Immucillins are logically designed transition-state analogue inhibitors of mammalian purine nucleoside phosphorylase (PNP) that induce purine-less death of Plasmodium falciparum in cultured erythrocytes (Kicska, G. A., Tyler, P. C., Evans, G. B., Furneaux, R. H., Schramm, V. L., and Kim, K. (2002) J. Biol. Chem. 277, 3226-3231). PNP is present at high levels in human erythrocytes and in P. falciparum, but the Plasmodium enzyme has not been characterized. A search of the P. falciparum genome data base yielded an open reading frame similar to the PNP from Escherichia coli. PNP from P. falciparum (P. falciparum PNP) was cloned, overexpressed in E. coli, purified, and characterized. The primary amino acid sequence has 26% identity with E. coli PNP, has 20% identity with human PNP, and is phylogenetically unique among known PNPs with equal genetic distance between PNPs and uridine phosphorylases. Recombinant P. falciparum PNP is catalytically active for inosine and guanosine but is less active for uridine. The immucillins are powerful inhibitors of P. falciparum PNP. Immucillin-H is a slow onset tight binding inhibitor with a Kii* value of 0.6 nM. Eight related immucillins are also powerful inhibitors with dissociation constants from 0.9 to 20 nM. The Km/Ki* value for immucillin-H is 9000, making this inhibitor the most powerful yet reported for P. falciparum PNP. The PNP from P. falciparum differs from the human enzyme by a lower Km for inosine, decreased preference for deoxyguanosine, and reduced affinity for the immucillins, with the exception of 5′-deoxy-immucillin-H. These properties of P. falciparum PNP are consistent with a metabolic role in purine salvage and provide an explanation for the antibiotic effect of the immucillins on P. falciparum cultured in human erythrocytes.
UR - http://www.scopus.com/inward/record.url?scp=0036479331&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036479331&partnerID=8YFLogxK
U2 - 10.1074/jbc.M105905200
DO - 10.1074/jbc.M105905200
M3 - Article
C2 - 11707439
AN - SCOPUS:0036479331
SN - 0021-9258
VL - 277
SP - 3219
EP - 3225
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 5
ER -