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Expression of the P-glycoprotein Homologue1 on food vacuoles isolated from Chloroquine-sensitive and resistant Plasmodium falciparum strains

Worldwide occurrence of chloroquine resistance is an expanding problem in prophylaxis and treatment of malaria. Similarities between the drug resistance phenotype in certain cancers and in malaria suggest that homologue multidrug resistance proteins might be involved in the mechanism of resistance....

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Main Author: Lindt, Meinrad
Other Authors: Smith, Peter J
Format: Thesis
Language:English
Published: Division of Clinical Pharmacology 2018
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access_status_str Open Access
author Lindt, Meinrad
author2 Smith, Peter J
author_browse Lindt, Meinrad
Smith, Peter J
author_facet Smith, Peter J
Lindt, Meinrad
author_sort Lindt, Meinrad
collection Thesis
description Worldwide occurrence of chloroquine resistance is an expanding problem in prophylaxis and treatment of malaria. Similarities between the drug resistance phenotype in certain cancers and in malaria suggest that homologue multidrug resistance proteins might be involved in the mechanism of resistance. In this thesis, the expression of a putative multidrug resistance protein of the malaria parasite Plasmodium falciparum, the P-glycoprotein homologue1 (Pgh1), was quantified on food vacuoles, the site of action of chloroquine. Chloroquine susceptibility was determined in 8 different P. falciparum strains. Food vacuoles were isolated from trophozoites of two chloroquine-sensitive (307 and D10) and three chloroquine-resistant (FAC8, K1 and RSA 11) strains. Antibodies against an 18 amino acid long peptide of Pgh1 were raised, as well as two other antibodies against the N-terminal ATP-binding site and the C-terminus of Pgh1. With these antibodies, Pgh1 was detected on isolated food vac.uoles and on trophozoites by immunoblotting. The exact Pgh1 expression levels on food vacuoles were measured with digital image analysis. The chloroquine-sensitive strains 307 and D10 and the chloroquine-resistant strains K1 and RSA 11 expressed equal amounts of Pgh1. The chloroquine-resistant FAC8 strain expressed at least three times more vacuolar Pgh1. No correlation was found between chloroquine IC₅₀ and vacuolar Pgh1 expression levels. Phosphorylation studies on intact food vacuoles indicated that Pgh1 is not a major kinase substrate.
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institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:31:34.243Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2018
publishDateRange 2018
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publisher Division of Clinical Pharmacology
publisherStr Division of Clinical Pharmacology
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source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/26932 Expression of the P-glycoprotein Homologue1 on food vacuoles isolated from Chloroquine-sensitive and resistant Plasmodium falciparum strains Lindt, Meinrad Smith, Peter J Folb, Peter I Pharmacology Worldwide occurrence of chloroquine resistance is an expanding problem in prophylaxis and treatment of malaria. Similarities between the drug resistance phenotype in certain cancers and in malaria suggest that homologue multidrug resistance proteins might be involved in the mechanism of resistance. In this thesis, the expression of a putative multidrug resistance protein of the malaria parasite Plasmodium falciparum, the P-glycoprotein homologue1 (Pgh1), was quantified on food vacuoles, the site of action of chloroquine. Chloroquine susceptibility was determined in 8 different P. falciparum strains. Food vacuoles were isolated from trophozoites of two chloroquine-sensitive (307 and D10) and three chloroquine-resistant (FAC8, K1 and RSA 11) strains. Antibodies against an 18 amino acid long peptide of Pgh1 were raised, as well as two other antibodies against the N-terminal ATP-binding site and the C-terminus of Pgh1. With these antibodies, Pgh1 was detected on isolated food vac.uoles and on trophozoites by immunoblotting. The exact Pgh1 expression levels on food vacuoles were measured with digital image analysis. The chloroquine-sensitive strains 307 and D10 and the chloroquine-resistant strains K1 and RSA 11 expressed equal amounts of Pgh1. The chloroquine-resistant FAC8 strain expressed at least three times more vacuolar Pgh1. No correlation was found between chloroquine IC₅₀ and vacuolar Pgh1 expression levels. Phosphorylation studies on intact food vacuoles indicated that Pgh1 is not a major kinase substrate. 2018-01-24T11:50:53Z 2018-01-24T11:50:53Z 1999 Master Thesis Masters MSc (Med) http://hdl.handle.net/11427/26932 eng application/pdf Division of Clinical Pharmacology Faculty of Health Sciences University of Cape Town
spellingShingle Pharmacology
Lindt, Meinrad
Expression of the P-glycoprotein Homologue1 on food vacuoles isolated from Chloroquine-sensitive and resistant Plasmodium falciparum strains
thesis_degree_str Master's
title Expression of the P-glycoprotein Homologue1 on food vacuoles isolated from Chloroquine-sensitive and resistant Plasmodium falciparum strains
title_full Expression of the P-glycoprotein Homologue1 on food vacuoles isolated from Chloroquine-sensitive and resistant Plasmodium falciparum strains
title_fullStr Expression of the P-glycoprotein Homologue1 on food vacuoles isolated from Chloroquine-sensitive and resistant Plasmodium falciparum strains
title_full_unstemmed Expression of the P-glycoprotein Homologue1 on food vacuoles isolated from Chloroquine-sensitive and resistant Plasmodium falciparum strains
title_short Expression of the P-glycoprotein Homologue1 on food vacuoles isolated from Chloroquine-sensitive and resistant Plasmodium falciparum strains
title_sort expression of the p glycoprotein homologue1 on food vacuoles isolated from chloroquine sensitive and resistant plasmodium falciparum strains
topic Pharmacology
url http://hdl.handle.net/11427/26932
work_keys_str_mv AT lindtmeinrad expressionofthepglycoproteinhomologue1onfoodvacuolesisolatedfromchloroquinesensitiveandresistantplasmodiumfalciparumstrains