Proteus vulgaris Urease: In vitro Inhibition by Urea Analogues.

Abstract

Summary Thirty-five analogues of urea have been evaluated for their ability to inhibit urease activity and growth of Proteus vulgaris ATCC 881. Enzyme activity was determined by the method of Chaney and Mar-bach. The ureolytic activity in a sonic lysate of Proteus vulgaris was markedly inhibited by thiourea, N-methylthiourea and N-acetyl-thiourea. The inhibition was not reversed by 10^-3 and 10^-4 M cysteine. None of the aryl substituted urea analogues had activity comparable to that of thiourea. Acetohydroxamic acid (1000 μg/ml) inhibited ureolytic activity of intact cells in Urea Broth (Difco) without concurrent growth inhibition. Chloro-acetylurea inhibited the growth of the test organism (125 μgg/ml), but failed to inhibit urease in Urea Broth or in sonic lysates. The capacity to inhibit urease activity in cell lysate does not appear to be associated with an ability to inhibit growth, or to inhibit ureolytic activity of intact cells.