Loading...
The 'pH optimum anomaly' of intracellular enzymes of Ferroplasma acidiphilum.
Golyshina, Olga V Golyshin, Peter N Timmis, Kenneth N Ferrer, Manuel
Golyshina, Olga V
Golyshin, Peter N
Timmis, Kenneth N
Ferrer, Manuel
Citations
Altmetric:
Advisors
Editors
Other Contributors
Issue Date
2006-03
Submitted date
Files
Loading...
original manuscript
Adobe PDF, 724.6 KB
Other Titles
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.
Citation
The 'pH optimum anomaly' of intracellular enzymes of Ferroplasma acidiphilum. 2006, 8 (3):416-25 Environ. Microbiol.
Publisher
Journal
PubMed ID
PubMed Central ID
Additional Links
Embedded video
Type
Article
Language
en
Description
Series/Report no.
ISSN
1462-2912