Abstract
A rapid sampling kinetic technique has been used to evaluate the nucleoside transport functions of Leishmania donovani. The results indicated that L. donovani promastigotes possessed two independent purine nucleoside transporters with nonoverlapping substrate specificity. The first transported inosine, guanosine, and their analogs, while the second carried adenosine, analogs of adenosine, and the pyrimidine nucleosides, uridine, cytidine, and thymidine. The apparent Km values of the two nucleoside permeases for their purine nucleoside substrates were extraordinarily low, in the micromolar range. The organisms were capable of concentrating purine nucleosides from the medium and converting them to the nucleotide level with great efficiency and rapidity. Inosine and adenosine transport could be distinguished by different sensitivities to sulfhydryl reagents, suggesting structural differences between the two transporters. Finally, the two nucleoside transport systems of L. donovani were virtually refractory to inhibition by 4-nitrobenzylthioinosine and dipyridamole, two potent inhibitors of nucleoside entry into mammalian cells.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 29-37 |
| Number of pages | 9 |
| Journal | Molecular and Biochemical Parasitology |
| Volume | 22 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2 1987 |
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Keywords
- Leishmania donovani
- Nucleoside transport
- Substrate specificity
ASJC Scopus subject areas
- Molecular Biology
- Parasitology
Cite this
Two high affinity nucleoside transporters in Leishmania donovani. / Aronow, Bruce; Kaur, Kiran; McCartan, Kathleen; Ullman, Buddy.
In: Molecular and Biochemical Parasitology, Vol. 22, No. 1, 02.01.1987, p. 29-37.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Two high affinity nucleoside transporters in Leishmania donovani
AU - Aronow, Bruce
AU - Kaur, Kiran
AU - McCartan, Kathleen
AU - Ullman, Buddy
PY - 1987/1/2
Y1 - 1987/1/2
N2 - A rapid sampling kinetic technique has been used to evaluate the nucleoside transport functions of Leishmania donovani. The results indicated that L. donovani promastigotes possessed two independent purine nucleoside transporters with nonoverlapping substrate specificity. The first transported inosine, guanosine, and their analogs, while the second carried adenosine, analogs of adenosine, and the pyrimidine nucleosides, uridine, cytidine, and thymidine. The apparent Km values of the two nucleoside permeases for their purine nucleoside substrates were extraordinarily low, in the micromolar range. The organisms were capable of concentrating purine nucleosides from the medium and converting them to the nucleotide level with great efficiency and rapidity. Inosine and adenosine transport could be distinguished by different sensitivities to sulfhydryl reagents, suggesting structural differences between the two transporters. Finally, the two nucleoside transport systems of L. donovani were virtually refractory to inhibition by 4-nitrobenzylthioinosine and dipyridamole, two potent inhibitors of nucleoside entry into mammalian cells.
AB - A rapid sampling kinetic technique has been used to evaluate the nucleoside transport functions of Leishmania donovani. The results indicated that L. donovani promastigotes possessed two independent purine nucleoside transporters with nonoverlapping substrate specificity. The first transported inosine, guanosine, and their analogs, while the second carried adenosine, analogs of adenosine, and the pyrimidine nucleosides, uridine, cytidine, and thymidine. The apparent Km values of the two nucleoside permeases for their purine nucleoside substrates were extraordinarily low, in the micromolar range. The organisms were capable of concentrating purine nucleosides from the medium and converting them to the nucleotide level with great efficiency and rapidity. Inosine and adenosine transport could be distinguished by different sensitivities to sulfhydryl reagents, suggesting structural differences between the two transporters. Finally, the two nucleoside transport systems of L. donovani were virtually refractory to inhibition by 4-nitrobenzylthioinosine and dipyridamole, two potent inhibitors of nucleoside entry into mammalian cells.
KW - Leishmania donovani
KW - Nucleoside transport
KW - Substrate specificity
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UR - http://www.scopus.com/inward/citedby.url?scp=0023151184&partnerID=8YFLogxK
U2 - 10.1016/0166-6851(87)90066-1
DO - 10.1016/0166-6851(87)90066-1
M3 - Article
C2 - 3807949
AN - SCOPUS:0023151184
VL - 22
SP - 29
EP - 37
JO - Molecular and Biochemical Parasitology
JF - Molecular and Biochemical Parasitology
SN - 0166-6851
IS - 1
ER -