How to kill a parasite : a report : an inhibitor study of ribose-5-phosphate isomerase B from Giardia lamblia as a possible drug target

The parasite Giardia lamblia is known to cause the disease giardiasis, which is a major threat against the public health, especially in developing countries. A recent study has shown that over 200 million people have giardiasis now, and about 500 000 more people are infected every year. A G. lamblia...

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Main Author: Steinhauf, Daniel
Format: M2
Language:Inglés
Published: SLU/Dept. of Molecular Biology (until 131231) 2010
Subjects:
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author Steinhauf, Daniel
author_browse Steinhauf, Daniel
author_facet Steinhauf, Daniel
author_sort Steinhauf, Daniel
collection Epsilon Archive for Student Projects
description The parasite Giardia lamblia is known to cause the disease giardiasis, which is a major threat against the public health, especially in developing countries. A recent study has shown that over 200 million people have giardiasis now, and about 500 000 more people are infected every year. A G. lamblia infection is usually treated with the drugs metronidazole, albendazole, tinidazole and furazolidone. These drugs are in some cases toxic and have severe side effects. Therefore new methods of killing the parasite are of great importance. Ribose-5-phosphate isomerase (Rpi) is an enzyme active in the pentose phosphate pathway, and it catalyses the conversion of ribose 5-phosphate to ribulose 5-phosphate and vice versa. Some enzymes in this class can also act on 6-carbon substrates, interconverting allose 6-phosphate and allulose 6-phosphate. To find which inhibitor works best on the enzyme from G. lamblia (GlRpiB), the enzyme was expressed as a His-tagged construct in E. coli was purified then tested to check its purity. When it was confirmed to be the right protein, the protein was used for crystallization and kinetic assays. Allose-6-phosphate was added before crystallization. Crystals formed in the presence of allose-6-phosphate. The Km, Vmax and kcat were determined and inhibitory tests were performed. It was determined that the Km for ribose-5-phosphate is about 10 mM, and the kcat is around 260sec-1. The Km of for allose-6-phosphate is 0.41 mM, and kcat 0.008sec-1. Among 6 substrate-like compounds tested, only 4PEH (4-phospho-D-erythronohydroxamic acid) showed significant inhibition of GlRpiB.
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institution Swedish University of Agricultural Sciences
language Inglés
publishDate 2010
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publisher SLU/Dept. of Molecular Biology (until 131231)
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spelling RepoSLU16242012-04-20T14:14:59Z How to kill a parasite : a report : an inhibitor study of ribose-5-phosphate isomerase B from Giardia lamblia as a possible drug target Hur man dödar en parasit : en rapport Steinhauf, Daniel Giardia lamblia Ribose-5-phosphate isomerase Giardiasis Inhibitor Parasite Diarrhea Pentose phosphate pathway 4PEH The parasite Giardia lamblia is known to cause the disease giardiasis, which is a major threat against the public health, especially in developing countries. A recent study has shown that over 200 million people have giardiasis now, and about 500 000 more people are infected every year. A G. lamblia infection is usually treated with the drugs metronidazole, albendazole, tinidazole and furazolidone. These drugs are in some cases toxic and have severe side effects. Therefore new methods of killing the parasite are of great importance. Ribose-5-phosphate isomerase (Rpi) is an enzyme active in the pentose phosphate pathway, and it catalyses the conversion of ribose 5-phosphate to ribulose 5-phosphate and vice versa. Some enzymes in this class can also act on 6-carbon substrates, interconverting allose 6-phosphate and allulose 6-phosphate. To find which inhibitor works best on the enzyme from G. lamblia (GlRpiB), the enzyme was expressed as a His-tagged construct in E. coli was purified then tested to check its purity. When it was confirmed to be the right protein, the protein was used for crystallization and kinetic assays. Allose-6-phosphate was added before crystallization. Crystals formed in the presence of allose-6-phosphate. The Km, Vmax and kcat were determined and inhibitory tests were performed. It was determined that the Km for ribose-5-phosphate is about 10 mM, and the kcat is around 260sec-1. The Km of for allose-6-phosphate is 0.41 mM, and kcat 0.008sec-1. Among 6 substrate-like compounds tested, only 4PEH (4-phospho-D-erythronohydroxamic acid) showed significant inhibition of GlRpiB. SLU/Dept. of Molecular Biology (until 131231) 2010 M2 eng https://stud.epsilon.slu.se/1624/
spellingShingle Giardia lamblia
Ribose-5-phosphate isomerase
Giardiasis
Inhibitor
Parasite
Diarrhea
Pentose phosphate pathway
4PEH
Steinhauf, Daniel
How to kill a parasite : a report : an inhibitor study of ribose-5-phosphate isomerase B from Giardia lamblia as a possible drug target
title How to kill a parasite : a report : an inhibitor study of ribose-5-phosphate isomerase B from Giardia lamblia as a possible drug target
title_full How to kill a parasite : a report : an inhibitor study of ribose-5-phosphate isomerase B from Giardia lamblia as a possible drug target
title_fullStr How to kill a parasite : a report : an inhibitor study of ribose-5-phosphate isomerase B from Giardia lamblia as a possible drug target
title_full_unstemmed How to kill a parasite : a report : an inhibitor study of ribose-5-phosphate isomerase B from Giardia lamblia as a possible drug target
title_short How to kill a parasite : a report : an inhibitor study of ribose-5-phosphate isomerase B from Giardia lamblia as a possible drug target
title_sort how to kill a parasite : a report : an inhibitor study of ribose-5-phosphate isomerase b from giardia lamblia as a possible drug target
topic Giardia lamblia
Ribose-5-phosphate isomerase
Giardiasis
Inhibitor
Parasite
Diarrhea
Pentose phosphate pathway
4PEH