Lsa30, a novel adhesin of Leptospira interrogans binds human plasminogen and the complement regulator C4bp.
Pathogenic Leptospira is the etiological agent of leptospirosis, a life-threatening disease that affects populations worldwide. Surface proteins have the potential to promote several activities, including adhesion. This work aimed to study the leptospiral coding sequence (CDS) LIC11087, genome annotated as hypothetical outer membrane protein. The LIC11087 gene was cloned and expressed in Escherichia coli BL21 (DE3) strain by using the expression vector pAE. The recombinant protein tagged with N-terminal 6XHis was purified by metal-charged chromatography and characterized by circular dichroism (CD) spectroscopy. The recombinant protein has the ability to mediate attachment to the extracellular matrix (ECM) components, laminin and plasma fibronectin, and was named Lsa30 (Leptospiral surface adhesin of 30 kDa). Lsa30 binds to laminin and to plasma fibronectin in a dose-dependent and saturable manner, with dissociation equilibrium constants (K(D)) of 292 ± 24 nm and 157 ± 35 nm, respectively. Moreover, the Lsa30 is a plasminogen (PLG) receptor, capable of generating plasmin, in the presence of activator. This protein may interfere with the complement cascade by interacting with C4bp regulator. The Lsa30 is probably a new surface protein of Leptospira as revealed by immunofluorescence assays with living organisms and the reactivity with antibodies present in serum samples of experimentally infected hamsters. Thus, Lsa30 is a novel versatile protein that may play a role in mediating adhesion and may help pathogenic Leptospira to overcome tissue barriers and to escape the immune system.
Centro de Biotecnologia, Instituto Butantan, Avenida Vital Brazil, 1500, 05503-900, São Paulo, SP, Brazil.
Natalie M
NM
Souza
Monica L
ML
Vieira
Ivy J
IJ
Alves
Zenaide M
ZM
de Morais
Silvio A
SA
Vasconcellos
Ana L T O
AL
Nascimento
D018829:Adhesins, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D050716:Complement C4b-Binding Protein; D003165:Complement System Proteins / Q000276:immunology*; D006224:Cricetinae; D005260:Female; D006649:Histocompatibility Antigens / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007921:Leptospira interrogans / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007922:Leptospirosis / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010958:Plasminogen / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D016415:Sequence Alignment
D018829:Adhesins, Bacterial; C055609:C4BPA protein, human; D050716:Complement C4b-Binding Protein; D006649:Histocompatibility Antigens; D010958:Plasminogen; D003165:Complement System Proteins