title: A domain of the Leptospira LigB contributes to high affinity binding of fibronectin.
abstract: Adhesion of pathogenic Leptospira spp. to mammalian cells is mediated by their adhesins interacting with host cell receptors. In a previous study, we have identified two potential fibronectin (Fn) binding sites in central variable region (LigBCen) and C-terminal variable region (LigBCtv) of LigB, an adhesin of pathogenic Leptospira spp. In this study, we have further localized the Fn-binding site on LigBCen and found a domain of LigB (LigBCen2) (amino acids 1014-1165) strongly bound to Fn. LigBCen2 bound to a 70kDa domain of Fn including N-terminal domain (NTD) and gelatin binding domain (GBD), but with a higher binding affinity to NTD (K(d)=272nM) than to GBD (K(d)=1200nM). Except Fn, LigBCen2 also bound laminin and fibrinogen. LigBCen2 could bind MDCK cells, and blocked the binding of Leptospira on MDCK cells by 45%. These results suggest that LigBCen2 contributed to high affinity binding on NTD or GBD of Fn, laminin, and fibrinogen and mediated Leptospira binding on host cells.
authors: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
authors: Yi-Pin
authors: YP
authors: Lin
authors: Yung-Fu
authors: YF
authors: Chang
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001422:Bacterial Adhesion; D001665:Binding Sites; D001667:Binding, Competitive; D002460:Cell Line; D006224:Cricetinae; D005353:Fibronectins / Q000737:chemistry / Q000378:metabolism*; D005780:Gelatin / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D007797:Laminin / Q000737:chemistry / Q000378:metabolism; D007919:Leptospira / Q000235:genetics / Q000378:metabolism*; D008647:Mesocricetus; D018613:Microscopy, Confocal; D008970:Molecular Weight; D011485:Protein Binding
chemical_list: D000942:Antigens, Bacterial; D005353:Fibronectins; D007797:Laminin; C487006:LigB-m protein, Leptospira interrogans; D005780:Gelatin