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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2010-6-29
pubmed:abstractText
Mitochondria were isolated from fresh beetroots (Beta vulgaris L. cvs Rubria and Nina) by differential centrifugation followed by Percoll gradient centrifugation. These purified mitochondria oxidized external NADH, although relatively slowly (20-40 versus 100-120 nanomoles oxygen per minute times milligram protein for NADH and succinate oxidation, respectively), with respiratory control ratios of two to three and ADP/O ratios of 1.2 to 1.6. NADPH was also oxidized, but even more slowly and with little or no coupling. The optimum for both NADH and NADPH oxidation by fresh beetroot mitochondria was pH 6. The rate of external NADH oxidation by isolated mitochondria was enhanced threefold during storage of the intact tubers at 10 degrees C for 12 weeks. The optimum of the induced NADH oxidation was approximately pH 6.8. Succinate and malate oxidation only increased by 30% during the same period and NADPH oxidation was constant. This is strong evidence that NADH and NADPH oxidation are catalyzed by different enzymes at least in beetroots. Activity staining of nondenaturing polyacrylamide gels with NADH and Nitro Blue Tetrazolium did not show differences in banding pattern between mitochondria isolated from fresh and stored beetroots. The induction is discussed in relation to physiological aging processes.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Sep
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
97
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
99-103
pubmed:dateRevised
2010-9-15
pubmed:year
1991
pubmed:articleTitle
Oxidation of External NAD(P)H by Purified Mitochondria from Fresh and Aged Red Beetroots (Beta vulgaris L.).
pubmed:affiliation
Department of Plant Physiology, University of Lund, Box 7007, S-220 07 Lund, Sweden.
pubmed:publicationType
Journal Article