Linked Life Data

7710318

Source:http://linkedlifedata.com/resource/pubmed/id/7710318

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-5-9
pubmed:databankReference
pubmed:abstractText
Archaeoglobus fulgidus is a hyperthermophilic sulfate-reducing archaeon. In this communication we describe the purification and properties of pyruvate: ferredoxin oxidoreductase from this organism. The catabolic enzyme was purified 250-fold to apparent homogeneity with a yield of 16%. The native enzyme had an apparent molecular mass of 120 kDa and was composed of four different subunits of apparent molecular masses of 45, 33, 25, and 13 kDa, indicating an alpha beta gamma delta structure. Per mol, the enzyme contained 0.8 mol thiamine pyrophosphate, 9 mol non-heme iron, and 8 mol acid-labile sulfur. FAD, FMN, lipoic acid, and copper were not found. The purified enzyme showed an apparent Km for coenzyme A of 0.02 mM, for pyruvate of 0.3 mM, and for clostridial ferredoxin of 0.01 mM, an apparent Vmax of 64 U/mg (at 65 degrees C) with a pH optimum near 7.5 and an Arrhenius activation energy of 75 kJ/mol (between 30 and 70 degrees C). The temperature optimum was above 90 degrees C. At 90 degrees C, the enzyme lost 50% activity within 60 min in the presence of 2 M KCl. The enzyme did not catalyze the oxidation of 2-oxoglutarate, indolepyruvate, phenylpyruvate, glyoxylate, and hydroxypyruvate. The N-terminal amino acid sequences of the four subunits were determined. The sequence of the alpha-subunit had similarities to the N-terminal amino acid sequence of the alpha-subunit of the heterotetrameric pyruvate: ferredoxin oxidoreductase from Pyrococcus furiosus and from Thermotoga maritima, and unexpectedly, to the N-terminal amino acid sequence of the homodimeric pyruvate:ferredoxin oxidoreductase from proteobacteria and from cyanobacteria. No sequence similarities were found, however, between the alpha-subunits of the enzyme from A. fulgidus and the heterodimeric pyruvate:ferredoxin oxidoreductase from Halobacterium halobium.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0302-8933
pubmed:author
pubmed:issnType
Print
pubmed:volume
163
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Pyruvate: ferredoxin oxidoreductase from the sulfate-reducing Archaeoglobus fulgidus: molecular composition, catalytic properties, and sequence alignments.
pubmed:affiliation
Laboratorium für Mikrobiologie des Fachbereichs Biologie der Philipps-Universität and Max-Planck-Institut für terrestrische Mikrobiologie, Marburg, Germany.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't