J Integr Plant Biol. ›› 1955, Vol. 4 ›› Issue (1): -.

• Research Articles •    

A Preliminary Report on the Synthesis of Aspartic Acid from Fumaric Acid and Ammonia with Aspartase Prepared from Higher Plants

Tang, Pei-sung Chow Pei-chen and Wang Tien-tuo   

Abstract: The conversion of ammonia and fumaric acid to aspartic acid is demonstrated in vitro withenzyme suspensions prepared from etiolated soybean and mung bean sprouts as well as from leaves of spinach and alfalfa, and from wheat seedlings The plant tissues were ground in Waling blendor, in presence of phosphate buffer pH 7.2. The pulp, after freeing from fibrous material, was twice precipitated with acetic acid at pH 4.6, centrifuged, and resuspended in phosphate buffer pH 7.2. To 8 ml of the above enzyme suspension were added 1 ml of 0.2 N sodium fumarate and 1 ml 0.2 N ammonium sulphate as reactants. The mixture was left to react, with the addition of a few drops of toluene to prevent bacterial growth, at 25℃ for 9,4 hours. At the end of the incubation period, the contents were chromatographed on filter paper with water-saturated phenol as solvent. A distinct spot of aspartic acid appeared after treatment with ninhydrin solution. It was taken to be the evidence of enzymic synthesis of aspartic acid since neither the enzyme suspension nor the reactants mixture incubated alone under the same condition produce any detectable amount of aspartic acid. That the aspartic acid formed is through direct addition of ammonia on to fumarate is demonstrated in the case of soybean by the inability of either succinate or malate to replace fumarate in this reaction.

Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2021 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q
备案号:京ICP备16067583号-22