125I-Labeled Peptide Mapping and High-Performance Liquid Chromatography I-Peptide Separation of Protein I of Four Strains ofNeisseria Gonorrhoeae

Abstract

¹²⁵I-labeled α-chymotryptic peptides of the principal outer membrane proteins (P.Is) of four strains of Neisseria gonorrhoeae were separated and visualized by two-dimensional (2-D) ¹²⁵I-peptide mapping and by high-performance liquid chromatography (HPLC) coupled with a Beckman Biogamma counter. In addition, ¹²⁵I-peptides were recovered from the HPLC separation and re-separated by the 2-D ¹²⁵I-peptide mapping system. The results indicated that the 2-D ¹²⁵I-peptide mapping procedure was best suited for comparative analyses of α-chymotryptic digests whereas the HPLC system, which is able to detect many more peptides than the 2-D system, is ideally suited for preparative separation of the ¹²⁵I-peptides. ¹²⁵I-peptides separated by HPLC could be recovered, rerun on the 2-D system, and the location of each peptide ascertained. The coupling of these two procedures allows for the isolation of specific ¹²⁵I-labeled peptides for further immunological and structural analyses of these outer membrane proteins.