2.50
Hdl Handle:
http://hdl.handle.net/10033/50053
Title:
The 'pH optimum anomaly' of intracellular enzymes of Ferroplasma acidiphilum.
Authors:
Golyshina, Olga V; Golyshin, Peter N; Timmis, Kenneth N; Ferrer, Manuel
Abstract:
A wide range of microorganisms, the so-called acidophiles, inhabit acidic environments and grow optimally at pH values between 0 and 3. The intracellular pH of these organisms is, however, close to neutrality or slightly acidic. It is to be expected that enzymatic activities dedicated to extracellular functions would be adapted to the prevailing low pH of the environment (0-3), whereas intracellular enzymes would be optimally active at the near-neutral pH of the cytoplasm (4.6-7.0). The genes of several intracellular or cell-bound enzymes, a carboxylesterase and three alpha-glucosidases, from Ferroplasma acidiphilum, a cell wall-lacking acidophilic archaeon with a growth optimum at pH 1.7, were cloned and expressed in Escherichia coli, and their products purified and characterized. The Ferroplasmaalpha-glucosidases exhibited no sequence similarity to known glycosyl hydrolases. All enzymes functioned and were stable in vitro in the pH range 1.7-4.0, and had pH optima much lower than the mean intracellular pH of 5.6. This 'pH optimum anomaly' suggests the existence of yet-undetected cellular compartmentalization providing cytoplasmic pH patchiness and low pH environments for the enzymes we have analysed.
Affiliation:
Division of Microbiology, GBF--German Research Centre for Biotechnology, Braunschweig, Germany.
Citation:
The 'pH optimum anomaly' of intracellular enzymes of Ferroplasma acidiphilum. 2006, 8 (3):416-25 Environ. Microbiol.
Journal:
Environmental microbiology
Issue Date:
Mar-2006
URI:
http://hdl.handle.net/10033/50053
DOI:
10.1111/j.1462-2920.2005.00907.x
PubMed ID:
16478448
Type:
Article
Language:
en
ISSN:
1462-2912
Appears in Collections:
Publications of RG Environmental Microbiology (UMW)

Full metadata record

DC FieldValue Language
dc.contributor.authorGolyshina, Olga V-
dc.contributor.authorGolyshin, Peter N-
dc.contributor.authorTimmis, Kenneth N-
dc.contributor.authorFerrer, Manuel-
dc.date.accessioned2009-02-23T14:17:40Z-
dc.date.available2009-02-23T14:17:40Z-
dc.date.issued2006-03-
dc.identifier.citationThe 'pH optimum anomaly' of intracellular enzymes of Ferroplasma acidiphilum. 2006, 8 (3):416-25 Environ. Microbiol.en
dc.identifier.issn1462-2912-
dc.identifier.pmid16478448-
dc.identifier.doi10.1111/j.1462-2920.2005.00907.x-
dc.identifier.urihttp://hdl.handle.net/10033/50053-
dc.description.abstractA wide range of microorganisms, the so-called acidophiles, inhabit acidic environments and grow optimally at pH values between 0 and 3. The intracellular pH of these organisms is, however, close to neutrality or slightly acidic. It is to be expected that enzymatic activities dedicated to extracellular functions would be adapted to the prevailing low pH of the environment (0-3), whereas intracellular enzymes would be optimally active at the near-neutral pH of the cytoplasm (4.6-7.0). The genes of several intracellular or cell-bound enzymes, a carboxylesterase and three alpha-glucosidases, from Ferroplasma acidiphilum, a cell wall-lacking acidophilic archaeon with a growth optimum at pH 1.7, were cloned and expressed in Escherichia coli, and their products purified and characterized. The Ferroplasmaalpha-glucosidases exhibited no sequence similarity to known glycosyl hydrolases. All enzymes functioned and were stable in vitro in the pH range 1.7-4.0, and had pH optima much lower than the mean intracellular pH of 5.6. This 'pH optimum anomaly' suggests the existence of yet-undetected cellular compartmentalization providing cytoplasmic pH patchiness and low pH environments for the enzymes we have analysed.en
dc.language.isoenen
dc.subject.meshArchaeal Proteinsen
dc.subject.meshCarboxylesteraseen
dc.subject.meshCloning, Molecularen
dc.subject.meshElectrophoresis, Gel, Two-Dimensionalen
dc.subject.meshEnzyme Stabilityen
dc.subject.meshEscherichia colien
dc.subject.meshHydrogen-Ion Concentrationen
dc.subject.meshMolecular Sequence Dataen
dc.subject.meshProteomeen
dc.subject.meshRecombinant Proteinsen
dc.subject.meshSequence Analysis, DNAen
dc.subject.meshSequence Homology, Amino Aciden
dc.subject.meshThermoplasmalesen
dc.subject.meshalpha-Glucosidasesen
dc.titleThe 'pH optimum anomaly' of intracellular enzymes of Ferroplasma acidiphilum.en
dc.typeArticleen
dc.contributor.departmentDivision of Microbiology, GBF--German Research Centre for Biotechnology, Braunschweig, Germany.en
dc.identifier.journalEnvironmental microbiologyen
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