Physiological Factors Regulating Tyrosine-sulphate Sulphohydrolase Activity in Cornamonas terrigena: Occurrence of Constitutive and Inducible Enzymes

Summary: Tyrosine-sulphate sulphohydrolase was synthesized by actively growing cultures and by resting suspensions of Comamonas terrigena. Polyacrylamide gel electrophoresis revealed that bacteria exposed to exogenous tyrosine sulphate synthesized two forms of this enzyme. Only one of these was detected in extracts of bacteria which had not been exposed to the ester. Both enzymes differed from aryl-sulphate sulphohydrolase in electrophoretic mobility. The synthesis of the induced form was regulated by tyrosine as well as by most intermediates of SO4 2− assimilation. L-Cysteine had no effect on the synthesis of the induced form but stimulated in vitro activity by about 85%. These effectors did not influence either the synthesis or the activity of the other electrophoretic form which was tentatively considered as being constitutive.