Isolation and characterization of the antigen of Neisseria gonorrhoeae.

The beta antigen of Neisseria gonorrhoeae has been isolated from the alkaline-extracted gonococcal endotoxin by ion exchange, molecular sieve, and powder block electrophoretic chromatography. Hemagglutination inhibition studies indicate that the preparation is essentially free of common enterobacterial and gonococcal alpha antigen. Analysis of the isolated antigen by immunodiffusion and acrylamide gel electrophoresis reveal only one detectable component. Chemical studies indicate that the antigen is an acidic glycoprotein composed primarily of four major amino acids: alanine, glutamic acid, glycine, and proline. The antigen has an s(20,w) of 8.55, and spectral analysis in the ultraviolet and visible range reveals a single absorption peak at 217 nm.