The cytotoxic lipid peroxidation product, 4-hydroxy-2-nonenal, specifically inhibits decarboxylating dehydrogenases in the matrix of plant mitochondria.
4-Hydroxy-2-nonenal (HNE), a cytotoxic product of lipid peroxidation, inhibits O(2) consumption by potato tuber mitochondria. 2-Oxoglutarate dehydrogenase (OGDC), pyruvate dehydrogenase complex (PDC) (both 80% inhibited) and NAD-malic enzyme (50% inhibited) are its major targets. Mitochondrial proteins identified by reaction with antibodies raised to lipoic acid lost this antigenicity following HNE treatment. These proteins were identified as acetyltransferases of PDC (78 kDa and 55 kDa), succinyltransferases of OGDC (50 kDa and 48 kDa) and glycine decarboxylase H protein (17 kDa). The significance of the effect of these inhibitions on the impact of lipid peroxidation and plant respiratory functions is discussed.
Millar
A H
AH
Plant Sciences Group, Department of Biochemistry, The University of Western Australia, Nedlands, Australia. hmillar@cyllene.uwa.edu.au
Leaver
C J
CJ
D000217:Acyltransferases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D000447:Aldehydes / Q000494:pharmacology*; D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D000906:Antibodies; D019069:Cell Respiration / Q000187:drug effects; D050961:Glycine Decarboxylase Complex H-Protein; D050841:Glycine Dehydrogenase (Decarboxylating); D007655:Ketoglutarate Dehydrogenase Complex / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D007656:Ketoglutaric Acids / Q000378:metabolism; D007700:Kinetics; D015227:Lipid Peroxidation; D008291:Malate Dehydrogenase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D008293:Malates / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology* / Q000378:metabolism; D008970:Molecular Weight; D010088:Oxidoreductases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D011768:Pyruvate Dehydrogenase Complex / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D019289:Pyruvic Acid / Q000378:metabolism; D011198:Solanum tuberosum / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D019802:Succinic Acid / Q000378:metabolism; D008063:Thioctic Acid / Q000378:metabolism
D000447:Aldehydes; D000906:Antibodies; D050961:Glycine Decarboxylase Complex H-Protein; D007656:Ketoglutaric Acids; D008293:Malates; D011768:Pyruvate Dehydrogenase Complex; D008063:Thioctic Acid; C030298:malic acid; D019289:Pyruvic Acid; D019802:Succinic Acid; D010088:Oxidoreductases; D008291:Malate Dehydrogenase; C046446:malate dehydrogenase-(oxaloacetate-decarboxylating) (NAD+); D007655:Ketoglutarate Dehydrogenase Complex; D000594:Amino Acid Oxidoreductases; D050841:Glycine Dehydrogenase (Decarboxylating); D000217:Acyltransferases; C027576:4-hydroxy-2-nonenal; D010100:Oxygen