Hemoglobin degradation in the human malaria pathogen Plasmodium falciparum: a catabolic pathway initiated by a specific aspartic protease

Hemoglobin is an important nutrient source for intraerythrocytic malaria organisms. Its catabolism occurs in an acidic digestive vacuole. Our previous studies suggested that an aspartic protease plays a key role in the degradative process. We have now isolated this enzyme and defined its role in the...

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Format: Online
Language:English
Published: The Rockefeller University Press 1991
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2190804/
id pubmed-2190804
recordtype oai_dc
spelling pubmed-21908042008-04-17 Hemoglobin degradation in the human malaria pathogen Plasmodium falciparum: a catabolic pathway initiated by a specific aspartic protease Articles Hemoglobin is an important nutrient source for intraerythrocytic malaria organisms. Its catabolism occurs in an acidic digestive vacuole. Our previous studies suggested that an aspartic protease plays a key role in the degradative process. We have now isolated this enzyme and defined its role in the hemoglobinolytic pathway. Laser desorption mass spectrometry was used to analyze the proteolytic action of the purified protease. The enzyme has a remarkably stringent specificity towards native hemoglobin, making a single cleavage between alpha 33Phe and 34Leu. This scission is in the hemoglobin hinge region, unraveling the molecule and exposing other sites for proteolysis. The protease is inhibited by pepstatin and has NH2-terminal homology to mammalian aspartic proteases. Isolated digestive vacuoles make a pepstatin- inhibitable cleavage identical to that of the purified enzyme. The pivotal role of this aspartic hemoglobinase in initiating hemoglobin degradation in the malaria parasite digestive vacuoles is demonstrated. The Rockefeller University Press 1991-04-01 /pmc/articles/PMC2190804/ /pubmed/2007860 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
repository_type Open Access Journal
institution_category Foreign Institution
institution US National Center for Biotechnology Information
building NCBI PubMed
collection Online Access
language English
format Online
title Hemoglobin degradation in the human malaria pathogen Plasmodium falciparum: a catabolic pathway initiated by a specific aspartic protease
spellingShingle Hemoglobin degradation in the human malaria pathogen Plasmodium falciparum: a catabolic pathway initiated by a specific aspartic protease
title_short Hemoglobin degradation in the human malaria pathogen Plasmodium falciparum: a catabolic pathway initiated by a specific aspartic protease
title_full Hemoglobin degradation in the human malaria pathogen Plasmodium falciparum: a catabolic pathway initiated by a specific aspartic protease
title_fullStr Hemoglobin degradation in the human malaria pathogen Plasmodium falciparum: a catabolic pathway initiated by a specific aspartic protease
title_full_unstemmed Hemoglobin degradation in the human malaria pathogen Plasmodium falciparum: a catabolic pathway initiated by a specific aspartic protease
title_sort hemoglobin degradation in the human malaria pathogen plasmodium falciparum: a catabolic pathway initiated by a specific aspartic protease
description Hemoglobin is an important nutrient source for intraerythrocytic malaria organisms. Its catabolism occurs in an acidic digestive vacuole. Our previous studies suggested that an aspartic protease plays a key role in the degradative process. We have now isolated this enzyme and defined its role in the hemoglobinolytic pathway. Laser desorption mass spectrometry was used to analyze the proteolytic action of the purified protease. The enzyme has a remarkably stringent specificity towards native hemoglobin, making a single cleavage between alpha 33Phe and 34Leu. This scission is in the hemoglobin hinge region, unraveling the molecule and exposing other sites for proteolysis. The protease is inhibited by pepstatin and has NH2-terminal homology to mammalian aspartic proteases. Isolated digestive vacuoles make a pepstatin- inhibitable cleavage identical to that of the purified enzyme. The pivotal role of this aspartic hemoglobinase in initiating hemoglobin degradation in the malaria parasite digestive vacuoles is demonstrated.
publisher The Rockefeller University Press
publishDate 1991
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2190804/
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