Intelectin-1 (INTL1) is a 120-kDa secretory lectin that recognizes multiple glycan epitopes found exclusively on microbes: beta-linked D-galactofuranose (beta-Galf), D-phosphoglycerol-modified glycans, heptoses, D-glycero-D-talo-oct-2-ulosonic acid (KO) and 3-deoxy-D-manno-oct-2-ulosonic acid (KDO) (Tsuji S et al. 2001; Wesener DA et al. 2015). These glycan residues are widely distributed in bacteria, including S. pneumoniae, Proteus mirabilis, Proteus vulgaris, Yersinia pestis and K. pneumoniae (Wesener DA et al. 2015). The 1.6-A-resolution crystal structure of human INTL1 complexed with beta-Galf suggests that INTL1 binds its carbohydrate ligands bearing terminal 1,2-diols through calcium ion-dependent coordination (Wesener DA et al. 2015).
Secreted INTL1 functions as a disulfide-linked trimer (Tsuji S et al., 2001; Tsuji S et al., 2007; Wesener DA et al., 2015).