title: Characterization of two new putative adhesins of Leptospira interrogans.
abstract: We here report the characterization of two novel proteins encoded by the genes LIC11122 and LIC12287, identified in the genome sequences of Leptospira interrogans, annotated, respectively, as a putative sigma factor and a hypothetical protein. The CDSs LIC11122 and LIC12287 have signal peptide SPII and SPI and are predicted to be located mainly at the cytoplasmic membrane of the bacteria. The genes were cloned and the proteins expressed using Escherichia coli. Proteinase K digestion showed that both proteins are surface exposed. Evaluation of interaction of recombinant proteins with extracellular matrix components revealed that they are laminin binding and they were called Lsa19 (LIC11122) and Lsa14 (LIC12287), for Leptospiral-surface adhesin of 19 and 14 kDa, respectively. The bindings were dose-dependent on protein concentration, reaching saturation, fulfilling the ligand-binding criteria. Reactivity of the recombinant proteins with leptospirosis human sera has shown that Lsa19 and, to a lesser extent, Lsa14, are recognized by antibodies, suggesting that, most probably, Lsa19 is expressed during infection. The proteins interact with plasminogen and generate plasmin in the presence of urokinase-type plasminogen activator. Plasmin generation in Leptospira has been associated with tissue penetration and immune evasion strategies. The presence of a sigma factor on the cell surface playing a secondary role, probably mediating host -pathogen interaction, suggests that LIC11122 is a moonlighting protein candidate. Although the biological significance of these putative adhesins will require the generation of mutants, our data suggest that Lsa19 is a potential candidate for future evaluation of its role in adhesion/colonization activities during L. interrogans infection.
authors.affiliation: Programa de Pós-Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, Avenida Prof. Lineu Prestes, 1730, São Paulo, SP 05508-900, Brazil.|Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, São Paulo, SP 05503-900, Brazil.
authors.forename: Jupciana M
authors.initials: JM
authors.lastname: Figueredo
authors.affiliation: Present address: Laboratorios de Investigação Medica, Hospital das Clínicas da FMUSP, Avenida Doutor Arnaldo, 455, São Paulo, SP 01246-903, Brazil.|Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, São Paulo, SP 05503-900, Brazil.
authors.forename: Gabriela H
authors.initials: GH
authors.lastname: Siqueira
authors.affiliation: Laboratório de Zoonoses Bacterianas do VPS, Faculdade de Medicina Veterinária e Zootecnia, USP, Avenida Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP 05508-270, Brazil.
authors.forename: Gisele O
authors.initials: GO
authors.lastname: de Souza
authors.affiliation: Laboratório de Zoonoses Bacterianas do VPS, Faculdade de Medicina Veterinária e Zootecnia, USP, Avenida Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP 05508-270, Brazil.
authors.forename: Marcos B
authors.initials: MB
authors.lastname: Heinemann
authors.affiliation: Laboratório de Zoonoses Bacterianas do VPS, Faculdade de Medicina Veterinária e Zootecnia, USP, Avenida Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP 05508-270, Brazil.
authors.forename: Silvio A
authors.initials: SA
authors.lastname: Vasconcellos
authors.affiliation: Centro de Controle de Zoonoses, R. Santa Eulália, 86 Santana, São Paulo, SP 02031-020, Brazil.
authors.forename: Erica G B
authors.initials: EGB
authors.lastname: Chapola
authors.affiliation: Programa de Pós-Graduação Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, USP, Avenida Prof. Lineu Prestes, 1730, São Paulo, SP 05508-900, Brazil.|Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, São Paulo, SP 05503-900, Brazil.
authors.forename: Ana L T O
authors.initials: ALTO
authors.lastname: Nascimento
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001422:Bacterial Adhesion / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D005341:Fibrinolysin / Q000378:metabolism; D016680:Genome, Bacterial / Q000235:genetics; D006801:Humans; D007921:Leptospira interrogans / Q000235:genetics* / Q000378:metabolism*; D007922:Leptospirosis / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D010958:Plasminogen / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics*
chemical_list: D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D012808:Sigma Factor; D010958:Plasminogen; D005341:Fibrinolysin