PURIFICATION AND PARTIAL CHARACTERIZATION OF THE OPACITY-ASSOCIATED PROTEINS OF NEISSERIA-GONORRHOEAE

Gonococci, grown on agar, frequently gave rise to opaque colonies. This opacity phenotype was associated with the presence of .gtoreq. 1 outer membrane proteins of .apprx. 28,000 MW. These proteins were included within a class of proteins named proteins II. A method is described to isolate and purify the opacity-associated proteins from N. gonorrhoeae. This method used high concentrations of Ca and a zwitterionic detergent at pH 4.0. Under these conditions proteins II were readily solubilized from the outer membrane. Further purification was achieved by ion exchange and molecular sieve chromatography in the presence of the zwitterionic detergent. The opacity-associated proteins were very basic with isoelectric points of 9.0-10.0. Further evidence for their basic nature was their behavior on ion exchange chromatography and their amino acid composition.