Transaminierung und Decarboxylierung von Ornithin und Lysin in höheren Pflanzen

Abstract

Zusammenfassung: Eine Aminosäure: 2-Oxosäure-Aminotransferase aus Lupinus angustifolius wird 21fach angereichert und charakterisiert. Ornithin und Lysin sind Substrate dieses Enzyms. Diese beiden Aminosäuren werden von den Transaminasen aus Lupinus angustifolius und Phaseolus aureus ROXB. im Sinne einer -Desaminierung umgesetzt. Lysin wird von Transaminasen aus Pseudomonas fluorescens und Flavobacterium flavescens dagegen in -Stellung desaminiert. In etiolierten Erbsenkeimlingen lassen sich Decarboxylasen für Ornithin und Lysin nachweisen. Dem Stoffwechsel von Ornithin und Lysin kommtSummary: An amino acid: 2-oxo acid-aminotransferase was purified 21-fold from Lupinus angustifolius. Ornithine and lysine are transaminated at the -amino group by the transaminases from Lupinus angustifolius and Phaseolus aureus ROXB. The transaminases of Pseudomonas fluorescens and Flavobacterium flavescens, however, transaminate lysine at the -position. Decarboxylases for ornithine and lysine were demonstrated in etiolated pea seedlings. The metabolism of ornithine and lysine is especially Transaminierung Eine Transaminierung von Ornithin und Lysin in höheren Pflanzen konnte mit Partikelpräparaten aus weißen Lupinen als Enzymmaterial beobachtet werden 1 . In Gegenwart 14 C-markierter oc-Oxoglutarsäure wird die Bildung von Glutaminsäure papierchromatographisch nachgewiesen. Der Umsatz von Ornithin und Lysin ist sehr gering. Für

Separation ofl-Leucine-pyruvate andl-Leucine-α-ketoglutarate Transaminases inAcetobacter suboxydansand Identification of Their Reaction Products

“…IO ) On the other hand, Hasse et al have found that the 21-fold purified transaminase from Lupinus angustifolius catalyzes the a-position transaminations of L-lysine and L-ornithine. 29 ) In this study, it was recognized that the L-leucine-pyruvate transaminase of A. suboxydans transferred the a-amino moiety of L-lysine to pyruvate, forming LP-piperideine-2-carboxylate, the cyclic compound of a-keto-s-aminocaproate; Lornithine was also transaminated at the aposition.…”

The Occurrence, Metabolism and Functions of Amines in Plants

“…A pyridoxal phosphate dependent enzyme which transaminates a-ketoglutaric acid with putrescine, cadaverine, hexamethylene diamine or heptamethylene diamine has been described in Escherichia coli (Kim & Tchen, 1962;Kim, 1963Kim, , 1964Yamada, Kimura, Tanaka & Ogata, 1964). Transaminase activity for a wide range of monoand diamines was also found in extracts of pea, tobacco, lupin and cauliflower tissues, and in Neurospora crmsa (Hasse & Schmid, 1963 ;Hasse et al 1967). Since the reaction is reversible it may provide an alternative biosynthetic pathway for these amines.…”

Imine Reductases: A Comparison of Glutamate Dehydrogenase to Ketimine Reductases in the Brain

“…There is, however, strong evidence that the conversion of L-ornithine to L-proline favors the ornithine α-aminotransferase pathway in several plant species (Fig. 3, enzyme reactions 5 followed by enzyme reaction 3) [45, 46]. Another possible route for the formation of KAV/Pyr2C is via oxidation of L-ornithine at the α-carbon by an LAAO reaction or by a dehydrogenase reaction.…”