Effeet of Metal Ions on Activity of Exopectic Acid Transeliminase of Erwinia sp

Contrary to the exopectic acid transeliminase of Clostridium multifermentans, that of Erwinia sp. was activated strongly by Na+ and to a much less extent by Ca2+. K+ had a small stimulating effect on the enzyme activity. Mn2+ and Co2+, like Ca2+, activated the enzyme weakly. Ba2+ and Mg2+ showed no and a slight inhibitory effect, respectively, on the activity.An almost total loss of activity was caused by the addition of EDTA to the reaction mixture. In the presence of Na+ the enzyme activity was restored by addition of divalent cations. Individual monovalent cations or each of the divalent cations was ineffective in restoring the activity.