dc.creatorBartoli, Carlos Guillermo
dc.creatorPastori, Gabriela M.
dc.creatorFoyer, Christine H.
dc.date2000
dc.date2021-08-27T15:15:25Z
dc.date.accessioned2023-07-15T02:53:50Z
dc.date.available2023-07-15T02:53:50Z
dc.identifierhttp://sedici.unlp.edu.ar/handle/10915/123635
dc.identifierissn:0032-0889
dc.identifierissn:1532-2548
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/7463683
dc.descriptionAscorbic acid is synthesized from galactono-γ-lactone (GL) in plant tissues. An improved extraction procedure involving ammonium sulfate precipitation of membrane proteins from crude leaf homogenates yielded a simple, quick method for determining tissue activities of galactono-γ-lactone dehydrogenase (GLDH). Total foliar ascorbate and GLDH activity decreased with leaf age. Subcellular fractionation experiments using marker enzymes demonstrated that 80% of the total GLDH activity was located on the inner mitochondrial membrane, and 20% in the microsomal fraction. Specific antibody raised against potato (Solanum tuberosum L.) tuber GLDH recognized a 56-kD polypeptide in extracts from the mitochondrial membranes but failed to detect the equivalent polypeptide in microsomes. We demonstrate that isolated intact mitochondria synthesize ascorbate in the presence of GL. GL stimulated mitochondrial electron transport rates. The respiration inhibitor antimycin A stimulated ascorbate biosynthesis, while cyanide inhibited both respiration and ascorbate production. GL-dependent oxygen uptake was observed in isolated intact mitochondria. This evidence suggests that GLDH delivers electrons to the mitochondrial electron transport chain between complexes III and IV.
dc.descriptionInstituto de Fisiología Vegetal
dc.formatapplication/pdf
dc.format335-344
dc.languageen
dc.rightshttp://creativecommons.org/licenses/by-nc-sa/4.0/
dc.rightsCreative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.subjectBotánica
dc.subjectAscorbate biosynthesis
dc.subjectMitochondria
dc.titleAscorbate Biosynthesis in Mitochondria Is Linked to the Electron Transport Chain between Complexes III and IV
dc.typeArticulo
dc.typeArticulo


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