L-Valine → L-Alanine

Participants

Reaction Steps

A solution of 2 ml of 0.6 M Valine-0.1 M KCl-1 mM EDTA, pH 9.8 was mixed with 100 μl (0.1 mmole) of a 1 M Bz-Ala-OMe (dissolved in 96% ethanol) solution. The reaction was carried out in a pH-stat at 35° C. and pH 9.8, the pH-value being kept constant by automatic addition of 0.5 M NaOH. The reaction was initiated by adding 0.7 mg of carboxypeptidase Y (150 U/mg, prepared by De Forenede Bryggerier). After a reaction time of 30 minutes, the reaction was discontinued by adjusting pH to about pH=1 with 6 M HCl. The reaction product was purified and isolated by means of high pressure chromatography. The yield of Bz-Ala-Val-OH was 40%. Quantitative amino acid analysis after hydrolysis of the product in 6 M HCl for 24 hours gave relatively 1.0 mole of Alanine and 1.0 mole of Valine.

Provenance & Evidence