Linked Life Data

9522466

Source:http://linkedlifedata.com/resource/pubmed/id/9522466

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1998-4-29
pubmed:abstractText
Lys606, one of the two highly conserved lysine residues in maize C4-form phosphoenolpyruvate carboxylase (PEPC), was converted to Asn, Glu or Arg by site-directed mutagenesis. Resulted mutant enzymes expressed using pET system [Dong, L.-Y. et al. (1997) Biosci. Biotech, Biochem. 61:545] were purified by one step procedure through nickel-chelate affinity chromatography to a purity of about 95%. The replacement of Lys606 by Arg had little effect on the kinetic and allosteric properties of the resulting mutant enzyme. In contrast, the maximum velocities (Vmax) were decreased to 22% and 2% of that of wild-type PEPC upon the substitution of Lys606 by Asn and Glu, respectively. The value of S0.5(HCO3-) was increased 21-25 fold by the replacements, whereas the S0.5(Mg2+) and S0.5(PEP) values were increased only 5-8 fold. The extents of activation of mutant enzymes by glucose 6-phosphate and glycine were 2 to 3-fold higher than those of wild-type enzyme. The mutant enzymes showed less sensitivity to malate inhibition, compared with the wild-type enzyme. The results suggested that the Lys606 is not obligatory for the enzyme activity, but may be involved in the bicarbonate-binding and contribute somehow to the allosteric regulatory properties.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0032-0781
pubmed:author
pubmed:issnType
Print
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1340-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Effects of site-directed mutagenesis of conserved Lys606 residue on catalytic and regulatory functions of maize C4-form phosphoenolpyruvate carboxylase.
pubmed:affiliation
Laboratory of Plant Physiology, Graduate School of Agriculture, Kyoto University, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't