Linked Life Data

16660615

Source:http://linkedlifedata.com/resource/pubmed/id/16660615

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2010-6-29
pubmed:abstractText
Cold lability of pyruvate, orthophosphate dikinase was investigated using a homogeneous, purified enzyme preparation from maize (Zea mays L. var. Golden Cross Bantam T51) leaves. Its stability was markedly reduced below about 10 C and the rate of cold inactivation followed first order kinetics at a concentration lower than about 0.1 milligram of enzyme per milliliter. Cold inactivation was little affected by pH in the range which gives good stability for the enzyme at warm temperatures and the enzyme activity was protected strongly by inclusion of substrates (pyruvate and phosphoenolpyruvate) and polyols such as sucrose, sorbitol, and glycerol. Loss of catalytic activity was accompanied by an apparent dissociation of a tetrameric form of the enzyme (9S form) into a new, more slowly sedimenting (5.1S) component. Inclusion of pyruvate at 4 mM in the cold-treated enzyme had no effect on the sedimentation value. A sharp change in activation energy of the dikinase-catalyzed reaction was observed near 12 C and its break point appears to be close to the generally accepted critical low temperature limit for the growth of maize plants.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Nov
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
62
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
826-30
pubmed:dateRevised
2010-9-14
pubmed:year
1978
pubmed:articleTitle
Cold lability of pyruvate, orthophosphate dikinase in the maize leaf.
pubmed:affiliation
Department of Agricultural Chemistry, School of Agriculture, Shizuoka University, 836 Ohya, Shizuoka 422, Japan.
pubmed:publicationType
Journal Article