The action of salts on fumarase. I

Abstract

B. coli commimis, washed and suspended in distilled water, produced Z-malic acid from fumaric acid at a linear rate for the greater part of the reaction until equilibrium was established. Side reactions were inhibited by 2 or 4% propyl alcohol. The range of activity was pH 5-7.7 in the absence of added salts, with an optimum at about 6.4. Phosphates accelerated the activity at pH 6-8.8, and the optimum activity was 6.9 for M/5 solutions. Citrates act similarly to phosphates but have a slightly higher optimum, pH 7.1. Sulphates had a retarding effect and the optimum was about pH 6.2.