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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
|
| pubmed:dateCreated |
1992-11-13
|
| pubmed:abstractText |
Cytoplasmic pyrophosphatase has been isolated from the thermoacidophilic archaebacterium Thermoplasma acidophilum. The enzyme was purified to electrophoretic homogeneity by combining ion-exchange and affinity-chromatographic separations. This soluble pyrophosphatase probably consists of six identical subunits, since SDS/PAGE gave an estimate of about 22 kDa for a single subunit and size-exclusion chromatography under non-denaturing conditions indicates a molecular mass of 110 +/- 5 kDa. The two most prominent catalytic features of this enzyme are the absolute requirement for divalent cations for catalytic action, Mg2+ conferring the highest activity, and the pronounced specificity for PPi. The catalytic behavior apparently follows simple Michaelis-Menten kinetics with a Km of about 7 microM for PPi and a specific activity of about 1200 U/mg at 56 degrees C. Surprisingly, maximum activity could be observed at 85 degrees C which is more than 20 degrees C above the temperature for optimal growth. Several cytoplasmic extracts of eubacteria and archaebacteria have been probed with a polyclonal antiserum raised against the purified archaebacterial protein. The only noticeable cross-reactivity could be detected with an extract from the methanogen Methanosarcina barkeri although this probably does not reflect the inferred phylogenetic relationship between methanogens and Thermoplasma acidophilum.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Cations, Divalent,
http://linkedlifedata.com/resource/pubmed/chemical/Inorganic Pyrophosphatase,
http://linkedlifedata.com/resource/pubmed/chemical/Magnesium,
http://linkedlifedata.com/resource/pubmed/chemical/Phenylglyoxal,
http://linkedlifedata.com/resource/pubmed/chemical/Pyrophosphatases
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0014-2956
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
1
|
| pubmed:volume |
209
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
343-9
|
| pubmed:dateRevised |
2007-7-23
|
| pubmed:meshHeading |
pubmed-meshheading:1327774-Amino Acid Sequence,
pubmed-meshheading:1327774-Blotting, Western,
pubmed-meshheading:1327774-Cations, Divalent,
pubmed-meshheading:1327774-Chromatography, Affinity,
pubmed-meshheading:1327774-Chromatography, Ion Exchange,
pubmed-meshheading:1327774-Cytoplasm,
pubmed-meshheading:1327774-Escherichia coli,
pubmed-meshheading:1327774-Hydrogen-Ion Concentration,
pubmed-meshheading:1327774-Immunoassay,
pubmed-meshheading:1327774-Inorganic Pyrophosphatase,
pubmed-meshheading:1327774-Kinetics,
pubmed-meshheading:1327774-Magnesium,
pubmed-meshheading:1327774-Methanosarcina,
pubmed-meshheading:1327774-Molecular Sequence Data,
pubmed-meshheading:1327774-Phenylglyoxal,
pubmed-meshheading:1327774-Pyrophosphatases,
pubmed-meshheading:1327774-Saccharomyces cerevisiae,
pubmed-meshheading:1327774-Substrate Specificity,
pubmed-meshheading:1327774-Temperature,
pubmed-meshheading:1327774-Thermoplasma
|
| pubmed:year |
1992
|
| pubmed:articleTitle |
Purification and enzymic characterization of the cytoplasmic pyrophosphatase from the thermoacidophilic archaebacterium Thermoplasma acidophilum.
|
| pubmed:affiliation |
Institut für Biochemie, Medizinische Universität zu Lübeck, Federal Republic of Germany.
|
| pubmed:publicationType |
Journal Article,
Comparative Study
|