+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Heme binding to Leishmania mexicana amazonensis

Molecular and Biochemical Parasitology, 291: 47-53

Heme binding to Leishmania mexicana amazonensis

Leishmania mexicana amazonensis is a pathogenic parasite whose growth, due to a biosynthetic deficiency, is dependent on a supply of exogenous heme. Utilizing [55Fe]hemin, we have demonstrated that heme binding to non-dividing cultured promastigotes of L. m. amazonensis at 4 degrees C reaches equilibrium within 6 h, is 95% dissociable by 28 h and is elevated approximately 5-fold by decreasing the pH of the binding buffer to 5.4. Metalloporphyrins substituted either at the central metal atom or in the porphyrin ring all displaced [55Fe]hemin binding to varying extents. Scatchard analysis revealed the affinity of the interaction to be 0.03 nM-1 and the number of binding sites to be 400 per promastigote. These findings are remarkably similar to those demonstrated in murine erythroleukemia cells and are characteristic of a receptor-ligand interaction. During logarithmic growth, promastigote heme binding was increased approximately 10-fold compared to stationary phase organisms. The increase was caused by a 4-fold greater number of binding sites per promastigote with no significant change in affinity. These findings demonstrate not only that L. m. amazonensis promastigotes bind heme specifically, but that the binding may be regulated by the growth phase of the parasite.

Accession: 001607389

PMID: 3386686

DOI: 10.1016/0166-6851(88)90118-1

Download PDF Full Text: Heme binding to Leishmania mexicana amazonensis

Related references

Heme requirement and acquisition by extracellular and intracellular stages of Leishmania mexicana amazonensis. Molecular and Biochemical Parasitology, 163: 267-276, 1985

Inhibition of growth of Leishmania mexicana mexicana by Leishmania mexicana amazonensis during "in vitro" co-cultivation. Memorias do Instituto Oswaldo Cruz 82(4): 537-542, 1987

Some methods for the enzymic characterization of Latin-American Leishmania with particular reference to Leishmania mexicana amazonensis and subspecies of Leishmania hertigi. Transactions of the Royal Society of Tropical Medicine and Hygiene 74(2): 243-252, 1980

Cutaneous leishmaniasis in Amazonia. Report of the 1st human case of mixed infection, determined by 2 different Leishmania species: Leishmania brasiliensis and Leishmania mexicana amazonensis. Revista do Instituto de Medicina Tropical de Sao Paulo 26(5): 272-275, 1984

Development of Leishmania mexicana and Leishmania amazonensis in Lutzomyia evansi Diptera Psychodidae, Phlebotomine Desarrollo de Leishmania mexicana y Leishmania amazonensis en Lutzomyia evansi Diptera Psychodidae, Phlebotomine. Revista Colombiana de Entomologia. Enero-Junio; 311: 71-74, 2005

The activity of plumbagin and other electron carriers against Leishmania donovani and Leishmania mexicana amazonensis. Annals of Tropical Medicine and Parasitology 79(6): 651-653, 1985

Accumulation of 125 Sb sodium stibogluconate by Leishmania mexicana amazonensis and Leishmania donovani in vitro. Comparative Biochemistry and Physiology C Comparative Pharmacology, 681: 95-98, 1981

Leishmania mexicana amazonensis and leishmania tarentolae carbohydrate composition a comparative study. Memorias do Instituto Oswaldo Cruz 82(SUPPL 1): 88, 1987

Ultrastructural and quantitative analysis of megasomes in Leishmania mexicana and Leishmania amazonensis. Memorias do Instituto Oswaldo Cruz 95(Suppl 2): 108, 2000

Development of Leishmania mexicana and Leishmania amazonensis in Lutzomyia evansi (Diptera: Psychodidae, Phlebotomine). Revista Colombiana de Entomologia 31(1): 71-74, 2005