Identification and Isolation of Surface-Exposed Portions of the Major Outer Membrane Protein ofChlamydia Trachomatisby Two-Dimensional Peptide Mapping and High-Performance Liquid Chromatography

Abstract

In this study, we use high-performance liquid chromatography (HPLC) to isolate surface-peptides of the Chlamydia trachomatis serotype G major outer membrane protein (G-MOMP). The HPLC elution profile was compared with that of peptides of the G-MOMP which was iodinated with chloro-T. Two-dimensional peptide mapping of chloro-T ¹²⁵I-labeled, surface-labeled peptides, and HPLC-isolated surface-peptides was then used to correlate HPLC-separated peptides with the 2-D maps of the G-MOMP. Results demonstrated that a 2-D-separated surface-peptide that had no apparent corresponding peptide in the 2-D chloro-T map was indeed present in the chloro-T labeled G-MOMP preparation, but at very low relative intensity, and that HPLC can be used to isolate surface-exposed regions of OM proteins for further immunological and structural studies.