Linked Life Data

4579

Source:http://linkedlifedata.com/resource/pubmed/id/4579

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1976-7-6
pubmed:abstractText
The pyruvate carboxylase of Pseudonomas fluorescens was purified 160-fold from cells grown on glucose at 20 degrees C. The activity of this purified enzyme was not affected by acetyl-coenzyme A or L-aspartate, but was strongly inhibited by ADP, which was competitive towards ATP. Pyruvate gave a broken double reciprocal plot, from which two apparent Km values could be determined, namely 0-08 and 0-21 mM, from the lower and the higher concentration ranges, respectively. The apparent Km for HCO3 at pH 6-9, in the presence of the manganese ATP ion (MnATP2-), was 3-1 mM. The enzyme reaction had an optimum pH value of 7-1 or 9-0 depending on the use of MnATP2- or MgATP2-, respectively, as substrate. Free Mg2+ was an activator at pH values below 9-0. The enzyme was strongly activated by monovalent cations; NH4+ and K+ were the better activators, with apparent Ka values of 0-7 and 1-6 mM, respectively. Partially purified enzymes from cells grown on glucose at 1 or 20 degrees C had the same properties, including the thermal stability. In both cases 50% of the enzyme activity was lost after pre-incubation for 10 min at 46 degrees C. The molecular weight was estimated to be about 300000 daltons by gel filtration on Sephadex G-200. The regulatory properties and molecular weight are thus similar to those determined for the pyruvate carboxylases from Pseudomonas citronellolis and Azotobacter vinelandii.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-1287
pubmed:author
pubmed:issnType
Print
pubmed:volume
93
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
75-81
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Some properties of the pyruvate carboxylase from Pseudomonas fluorescens.
pubmed:publicationType
Journal Article