We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK


97% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Isolation of the biunctional enzyme lysine 2-ox...
View graph of relations

« Back

Isolation of the biunctional enzyme lysine 2-oxoglutarate reductase-saccharopine dehydrogenase from Phaseolus vulgaris.

Research output: Contribution to journalJournal article


  • S. T. C. Lima
  • R. A. Azevedo
  • L. G. Santoro
  • S. A. Gaziola
  • P. J. Lea
<mark>Journal publication date</mark>03/2003
<mark>Journal</mark>Amino Acids
Number of pages8
<mark>Original language</mark>English


Lysine is catabolyzed by the bifunctional enzyme lysine 2-oxoglutarate reductase-saccharopine dehydrogenase (LOR-SDH) in both animals and plants. LOR condenses lysine and 2-oxoglutarate into saccharopine, using NADPH as cofactor and SDH converts saccharopine into α-aminoadipate δ-semialdehyde and glutamic acid, using NAD as cofactor. The distribution pattern of LOR and SDH among different tissues of Phaseolus vulgaris was determined. The hypocotyl contained the highest specific activity, whereas in seeds the activities of LOR and SDH were below the limit of detection. Precipitation of hypocotyl proteins with increasing concentrations of PEG 8000 revealed one broad peak of SDH activity, indicating that two isoforms may be present, a bifunctional LOR-SDH and possibly a monofunctional SDH. During the purification of the hypocotyl enzyme, the LOR activity proved to be very unstable, following ion-exchange chromatography. Depending on the purification procedure, the protein eluted as a monomer of 91–94 kDa containing only SDH activity, or as a dimer of 190 kDa with both, LOR and SDH activities, eluting together.