| Abstract: | Among organisms in the class Mollicutes only Ureaplasma species possess urease. Antiserum to urease of U. urealyticum strain T960 (CX8) was used to examine the cross-reactivity of urease from other Ureaplasma species, as well as urease of jack bean and several urease-possessing walled bacteria. Immunological cross reactivity was used to establish phylogenetic relationships between various antigens. The ability of monospecific anti-urease antibody to inhibit urease activity was examined. The antiserum inhibited urease activity of the homologous strain the least of any Ureaplasma tested. It is postulated that urease possesses a minimum of two sets of epitopes. Binding of antibody to one epitope causes inhibition of enzyme activity; this epitope is common to urease of all Ureaplasma species. Binding of antibody to the other epitope prevents binding to the inhibition epitope; this epitope is specific to U. urealyticum strain T960 (CX8). No inhibition was observed with urease from jack bean or several walled bacteria. |
