IDENTIFICATION OF THE TREPONEMA-PALLIDUM SUBSP PALLIDUM GLYCEROPHOSPHODIESTER PHOSPHODIESTERASE HOMOLOG

To identify potential opsonic targets of Treponema pallidum subsp. pal lidum, a treponemal genomic expression library was constructed and dif ferentially screened with opsonic and non-opsonic T. pallidum antisera . This method identified an immunoreactive clone containing an open re ading frame encoding a 356 residue protein. Nucleotide sequence analys is demonstrated the translated protein to be a homologue of glyceropho sphodiester phosphodiesterase, a glycerol metabolizing enzyme previous ly identified in Haemophilus influenzae, Escherichia coli, Bacillus su btilis and Borrelia hermsii. Sequence alignment analyses revealed the T. pallidum and H. influenzae enzymes share a high degree of amino aci d sequence similarity (72%), suggesting that in T. pallidum this molec ule may be surface exposed and involved in IgD binding as is the case with its counterpart in H. influenzae.