Linked Life Data

1651917

Source:http://linkedlifedata.com/resource/pubmed/id/1651917

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
1991-9-26
pubmed:abstractText
The 34-kDa subunit of rat liver phosphoribosylpyrophosphate synthetase is a mixture of the two highly homologous isoforms, PRS I and PRS II. Heretofore, it was not possible to separate the two. We now describe isolation and characterization of the recombinant isoforms, named rPRS I and rPRS II. The respective rat cDNAs were inserted into vectors constructed from pKK233-2 by replacing its replication origin with that of pGEM-1 and expressed in Escherichia coli. The rPRS I and rPRS II were purified to apparent homogeneity with specific activities of 33,400 and 46,200 milliunits/mg, respectively; these values were at least 2.5-fold higher than the highest value for the mammalian enzyme so far reported. Both isoforms showed a similar dependency on Pi as an absolute activator. Sulfate partially substituted for Pi. The maximal activities of rPRS I and rPRS II with sulfate were 43 and 7%, respectively, of those seen with Pi. The two isoforms differed in sensitivity to inhibition by ADP and GDP. Inhibition of rPRS I and rPRS II by 0.3 mM ADP was 87 and 54%, respectively, and inhibition by 1 mM GDP was 93 and 24%, respectively. rPRS II was 180-fold more sensitive than rPRS I to heat inactivation at 49 degrees C.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15693-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Expression of rat phosphoribosylpyrophosphate synthetase subunits I and II in Escherichia coli. Isolation and characterization of the recombinant isoforms.
pubmed:affiliation
Department of Biochemistry, Chiba University School of Medicine, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't