A soluble 60 kiloDalton antigen of Chlamydia spp. is a homologue of Escherichia coli GroEL.
Two major 60 kD protein species can be separated by differential detergent extraction in Chlamydia spp. A Sarkosyl-soluble 60 kD protein is (i) structurally and antigenically distinct from the previously characterized 60 kD Omp2 outer membrane protein; and (ii) antigenically related to a bacterial common antigen of similar molecular weight which includes a 65 kD mycobacterial antigen and the GroEL heat-shock protein of Escherichia coli. Among GroEL homologues, the chlamydial protein (chl-GroEL) uniquely displays affinity towards immobilized thiol groups. The significance of this property is discussed with respect to the synthesis and assembly of the chlamydial disulphide-rich cell wall late in the growth cycle. Chl-GroEL is identical to the Triton X-100-soluble, ocular delayed-type hypersensitivity agent (Morrison et al., 1989), an essential component in the development of blinding trachoma. An autoimmune mechanism for chronic chlamydial diseases based on chl-GroEL homology to host proteins is hypothesized.
Bavoil
P
P
Department of Microbiology and Immunology, University of Rochester Medical Center, New York 14642.
Stephens
R S
RS
Falkow
S
S
D000942:Antigens, Bacterial / Q000302:isolation & purification*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology / Q000302:isolation & purification*; D018834:Chaperonin 60; D002689:Chlamydia / Q000032:analysis / Q000276:immunology*; D004926:Escherichia coli / Q000032:analysis / Q000276:immunology*; D006360:Heat-Shock Proteins / Q000276:immunology / Q000302:isolation & purification*; D008970:Molecular Weight; D012995:Solubility; D013438:Sulfhydryl Compounds / Q000378:metabolism
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D018834:Chaperonin 60; D006360:Heat-Shock Proteins; D013438:Sulfhydryl Compounds