Identification of lactoferrin-binding proteins from Treponema pallidum subspecies pallidum and Treponema denticola.
Lactoferrin-binding or -associated proteins were identified in Treponema pallidum subspecies pallidum and Treponema denticola by affinity column chromatography using human lactoferrin and detergent-solubilized, radiolabelled spirochaetes. Two discrete polypeptides of T. pallidum with masses of 45 and 40 kDa and a broad band from 29-34 kDa exhibited association with human apo- and partially ferrated lactoferrin. T. denticola produced two proteins that associated with a lactoferrin affinity matrix (50 and 35 kDa). T. pallidum and T. denticola did not associate with soluble, human transferrin in parallel experiments. Soluble human lactoferrin competed with all lactoferrin-associated proteins from T. pallidum and T. denticola in competitive-binding assays. However, the T. denticola proteins dissociated from a lactoferrin-affinity matrix in the presence of differing concentrations of unlabelled, soluble lactoferrin competitor. Treatment with phospholipase D altered migration of the diffuse 29-34 kDa band of T. pallidum suggesting that the polypeptide was lipid-modified. Each of the lactoferrin-binding proteins from T. pallidum and T. denticola reacted with pooled rabbit syphilitic antisera. The lactoferrin-binding proteins of T. pallidum reacted with human sera from patients at all stages of syphilis. In addition, a monoclonal antibody generated against the 45 kDa polypeptide of T. pallidum crossreacted with the 29-34 kDa protein.
Staggs
T M
TM
Department of Microbiology, University of Texas Health Science Center at San Antonio 78284-7758.
Greer
M K
MK
Baseman
J B
JB
Holt
S C
SC
Tryon
V V
VV
D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D002846:Chromatography, Affinity; D006801:Humans; D066298:In Vitro Techniques; D007781:Lactoferrin / Q000378:metabolism*; D008970:Molecular Weight; D013587:Syphilis / Q000276:immunology; D014208:Treponema / Q000378:metabolism*; D014210:Treponema pallidum / Q000378:metabolism*
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; C027768:lactoferrin binding proteins, bacterial; D007781:Lactoferrin