Levodopa → N-(4-Amino-4-carboxy-1-hydroxybutylidene)-3-hydroxytyrosine

Participants

Reaction Steps

Glutathione and L-DOPA were incubated with a partially purified preparation of sheep kidney γ-glutamyl transpeptidase. γ-Glutamyl-DOPA was isolated from the incubation mixture by preparative ion exchange chromatography on a Dowex-1 (acetate) column. 6.14 of glutathione (0.02 mole) and 1.97 g of L-DOPA (0.01 mole) were dissolved in 200 ml of 1 M Tris (base) solution. 2.5 ml of γ-glutamyl transpeptidase solution (100 units/ml) were added and the flask was flushed with nitrogen to protect DOPA from oxidation and the mixture was incubated at 37° for 6 hours. L-γ-glutamyl-L-3,4-dihydroxyphenylalanine (γ-glutamyl-DOPA) was isolated by ion exchange chromatography as in Example 1. It emerges from the column when approximately 2 liters of the eluent passed through the column. Unreacted. glutathione, free glutamate and cysteinylglycine emerge from the column in earlier fractions.

Provenance & Evidence