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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-1-6
pubmed:abstractText
In situ Fourier transform infrared microspectroscopy was used to study the heat stability of proteins and hydrogen bonding interactions in dry maturation-defective mutant seeds of Arabidopsis thaliana. alpha-Helical, turn and beta-sheet conformations were the major protein secondary structures in all of these seeds. On heating, intermolecular extended beta-sheet structures, typical of protein denaturation, were formed in abscisic acid-insensitive (abi3) and leafy cotyledon (lec) mutant seeds. Proteins in dry wild-type seeds did not denature up to 150 degrees C, but those in dry desiccation-sensitive, lec1-1, lec1-3 and abi3-5 seeds did at 68, 89 and 87 degrees C, respectively. In the desiccation-tolerant abi3-7 and abi3-1 seeds, denaturation commenced above 120 and 135 degrees C, respectively. Seeds of the aba1-1 abi3-1 double mutant showed signs of denaturation already upon drying. The molecular packing in the seeds was studied by observing the shift in the position of the OH-stretching vibration band with temperature. The maximal rate of change of this band with temperature was much higher in the desiccation-sensitive abi3-5, aba1-1 abi3-1, lec1-1, and lec1-3 mutant seeds than in the desiccation-tolerant wild-type, abi3-1, abi3-7, and lec2-1 seeds. We interpret this to mean that the molecular packing density is higher in dry desiccation-tolerant than in dry desiccation-sensitive seeds, which is associated with a higher or lower protein denaturation temperature, respectively. The results are discussed in relation to the physiological and biochemical characteristics of these mutant seeds.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0960-7412
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
133-43
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Properties of proteins and the glassy matrix in maturation-defective mutant seeds of Arabidopsis thaliana.
pubmed:affiliation
Department of Biomolecular Sciences, Wageningen Agricultural University, The Netherlands. Wim.Wolkers@algem.pf.wau.nl
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't