Biomaterial Database

Biochemistry and regulation of folate and methotrexate transport in Leishmania major. 1987

T E Ellenberger, and S M Beverley

Promastigotes of the protozoan parasite Leishmania major exhibit high affinity uptake of folate (Kt = 0.7 microM) and methotrexate (MTX) (Kt = 1.8 microM) which is saturable and sensitive to metabolic poisons. Influx of folate and MTX is competitively inhibited by 5-formyltetrahydrofolate and p-aminobenzoic acid-glutamate, but not by 4-deoxy-4-amino-10-methylpteroate, biopterin, or pteroate. A single carrier is inferred for both folate and MTX transport, as the Ki of each inhibitor for both folate and MTX influx is the same, and the apparent affinities (Kt) of the substrates folate and MTX are identical to their respective Ki values for inhibition of MTX and folate uptake. Folate influx is specifically regulated according to cellular growth phase, as stationary phase cells exhibit 7% of the Vmax of log phase cells, while energy-dependent glucose uptake is only moderately reduced in stationary phase. Folate influx is also regulated by external folate levels, as cells grown in 5 microM folate exhibit 30% of the Vmax of cells grown in folate-depleted medium. Comparison of bacterial, mammalian, and Leishmania folate transport activities indicates considerable diversity in both biochemical and regulatory properties, and suggests the possibility that selective inhibition or manipulation of folate transport may be exploited in parasite chemotherapy.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007895	Leishmania tropica	A parasitic hemoflagellate of the subgenus Leishmania leishmania that infects humans and rodents. This taxonomic complex includes species which cause a disease called Oriental sore which is a form of cutaneous leishmaniasis (LEISHMANIASIS, CUTANEOUS) of the Old World.	Leishmania (Leishmania) tropica,Leishmania tropica minor,Leishmania leishmania tropica,Leishmania tropicas
D008727	Methotrexate	An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of TETRAHYDROFOLATE DEHYDROGENASE and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA.	Amethopterin,Methotrexate Hydrate,Methotrexate Sodium,Methotrexate, (D)-Isomer,Methotrexate, (DL)-Isomer,Methotrexate, Dicesium Salt,Methotrexate, Disodium Salt,Methotrexate, Sodium Salt,Mexate,Dicesium Salt Methotrexate,Hydrate, Methotrexate,Sodium, Methotrexate
D010129	4-Aminobenzoic Acid	An aminobenzoic acid isomer that combines with pteridine and GLUTAMIC ACID to form FOLIC ACID. The fact that 4-aminobenzoic acid absorbs light throughout the UVB range has also resulted in its use as an ingredient in SUNSCREENS.	PABA,p-Aminobenzoic Acid,para-Aminobenzoic Acid,4-Aminobenzoic Acid, Potassium Salt,Aminobenzoic Acid (USP),Epit Vit,Epitelplast,Hachemina,Magnesium para-Aminobenzoate,Pabasan,Paraminan,Paraminol,Potaba,Potassium 4-Aminobenzoate,Potassium Aminobenzoate,4 Aminobenzoic Acid,4 Aminobenzoic Acid, Potassium Salt,4-Aminobenzoate, Potassium,Aminobenzoate, Potassium,Potassium 4 Aminobenzoate,p Aminobenzoic Acid,para Aminobenzoic Acid,para-Aminobenzoate, Magnesium
D002955	Leucovorin	The active metabolite of FOLIC ACID. Leucovorin is used principally as an antidote to FOLIC ACID ANTAGONISTS.	Calcium Leucovorin,Citrovorum Factor,Folinic Acid,N(5)-Formyltetrahydrofolate,5-Formyltetrahydrofolate,5-Formyltetrahydropteroylglutamate,Calcium Folinate,Folinic Acid-SF,Leucovorin, (D)-Isomer,Leucovorin, (DL)-Isomer,Leucovorin, (R)-Isomer,Leucovorin, Calcium (1:1) Salt,Leucovorin, Calcium (1:1) Salt, (DL)-Isomer,Leucovorin, Calcium (1:1) Salt, Pentahydrate,Leucovorin, Monosodium Salt,Leukovorin,Leukovorum,Wellcovorin,5 Formyltetrahydrofolate,5 Formyltetrahydropteroylglutamate,Acid, Folinic,Factor, Citrovorum,Folinate, Calcium,Folinic Acid SF,Leucovorin, Calcium,Monosodium Salt Leucovorin
D003847	Deoxyglucose	2-Deoxy-D-arabino-hexose. An antimetabolite of glucose with antiviral activity.	2-Deoxy-D-glucose,2-Deoxyglucose,2-Desoxy-D-glucose,2 Deoxy D glucose,2 Deoxyglucose,2 Desoxy D glucose
D005492	Folic Acid	A member of the vitamin B family that stimulates the hematopoietic system. It is present in the liver and kidney and is found in mushrooms, spinach, yeast, green leaves, and grasses (POACEAE). Folic acid is used in the treatment and prevention of folate deficiencies and megaloblastic anemia.	Pteroylglutamic Acid,Vitamin M,Folacin,Folate,Folic Acid, (D)-Isomer,Folic Acid, (DL)-Isomer,Folic Acid, Calcium Salt (1:1),Folic Acid, Monopotassium Salt,Folic Acid, Monosodium Salt,Folic Acid, Potassium Salt,Folic Acid, Sodium Salt,Folvite,Vitamin B9,B9, Vitamin
D005971	Glutamates	Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure.	Glutamic Acid Derivatives,Glutamic Acids,Glutaminic Acids
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001693	Biological Transport, Active	The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.	Active Transport,Uphill Transport,Active Biological Transport,Biologic Transport, Active,Transport, Active Biological,Active Biologic Transport,Transport, Active,Transport, Active Biologic,Transport, Uphill