H. A. Barker

GLUTAMATE MUTASE REACTION.

(previously called glutamate isomerase) reaction is of special interest because it is one of only two enzymatic reactions known to cause a direct rearrangement of the carbon skeleton of a substrate and because it is one of a few reactions presently known to require a cobamide coenzyme.3~~ A thorough study of the enzyme and of the reaction it catalyzes should ultimately give an insight into the mechanism of action of the coenzyme. This goal is not yet in sight. The work so far done with the mutase has been largely preparatory. We have developed methods to assay for the enzyme and to purify it sufficiently so that it has satisfactory optical properties and is free of interfering activities. We have determined the essential conditions for mutase activity and have established the nature and specificity of the enzymatic reaction in which the coenzyme participates. Finally, we have looked for the occurrence of several types of exchange of reactions that could give some indication of the mechanism of the mutase reaction. We shall attempt to summarize the available information concerning the mutase and the reaction it catalyzes. Spectrophotometric assay for glutamate mutase activity. A spectrophotometric assay was developed several years ago that is suitable for the

Enzymic Preparation of L-β-Lysine

Abstract L-β-Lysine is prepared from L-lysine by the action of an enzyme, L-lysine-2, 3-aminomutase, present in extracts of lysine-fermenting Clostridia. 1The basic amino acids in the reaction mixture are adsorbed on a cation exchange resin, and β-lysine is separated from residual lysine by differential elution at pH 3.0. The β-lysine is desalted by adsorbing it on a cation exchange resin, washing the resin with water and eluting the 8-lysine with ammonia. Ammonia is removed and the β-lysine is converted to the sulfate and crystallized from aqueous methanol. The yield is 123 milli-moles or 61% based on the initial amount of lysine.

Enzymic preparation of L-beta-lysine.

Abstract L-β-Lysine is prepared from L-lysine by the action of an enzyme, L-lysine-2, 3-aminomutase, present in extracts of lysine-fermenting Clostridia. 1The basic amino acids in the reaction mixture are adsorbed on a cation exchange resin, and β-lysine is separated from residual lysine by differential elution at pH 3.0. The β-lysine is desalted by adsorbing it on a cation exchange resin, washing the resin with water and eluting the 8-lysine with ammonia. Ammonia is removed and the β-lysine is converted to the sulfate and crystallized from aqueous methanol. The yield is 123 milli-moles or 61% based on the initial amount of lysine.

Enzymic Preparation ofL-β-Lysine

Abstract L-β-Lysine is prepared from L-lysine by the action of an enzyme, L-lysine-2, 3-aminomutase, present in extracts of lysine-fermenting Clostridia. 1The basic amino acids in the reaction mixture are adsorbed on a cation exchange resin, and β-lysine is separated from residual lysine by differential elution at pH 3.0. The β-lysine is desalted by adsorbing it on a cation exchange resin, washing the resin with water and eluting the 8-lysine with ammonia. Ammonia is removed and the β-lysine is converted to the sulfate and crystallized from aqueous methanol. The yield is 123 milli-moles or 61% based on the initial amount of lysine.