Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Isolation of the biunctional enzyme lysine 2-oxoglutarate reductase-saccharopine dehydrogenase from Phaseolus vulgaris.
AU - Lima, S. T. C.
AU - Azevedo, R. A.
AU - Santoro, L. G.
AU - Gaziola, S. A.
AU - Lea, P. J.
PY - 2003/3
Y1 - 2003/3
N2 - 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.
AB - 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.
KW - Phaseolus vulgaris - Catabolism - Lysine - Lysine 2-oxoglutarate reductase - Saccharopine dehydrogenase
U2 - 10.1007/s00726-002-0315-7
DO - 10.1007/s00726-002-0315-7
M3 - Journal article
VL - 24
SP - 179
EP - 186
JO - Amino Acids
JF - Amino Acids
SN - 0939-4451
IS - 1-2
ER -