Identification of a new adhesin-like protein from Lactobacillus mucosae ME-340 with specific affinity to the human blood group A and B antigens

To identify and characterize a new adhesin-like protein of probiotics that show specific adhesion to human blood group A and B antigens. Using the BIACORE assay, the adhesion of cell surface components obtained from four lactobacilli strains that adhered to blood group A and B antigens was tested. Their components showed a significant adhesion to A and B antigens when compared to the bovine serum albumin (BSA) control. The 1 mol l⁻¹ GHCl fraction extracted from Lactobacillus mucosae ME-340 contained a 29-kDa band (Lam29) using SDS-PAGE. The N-terminal amino acid sequence and homology analysis showed that Lam29 was 90% similar to the substrate-binding protein of the ATP-binding cassette (ABC) transporter from Lactobacillus fermentum IFO 3956. The complete nucleotide sequence (858 bp) of Lam29 was determined and encoded a protein of 285 amino acid residues. Phylogenetic analysis and multiple sequence alignments indicated this protein may be related to the cysteine-binding transporter. The adhesion of ME-340 strain to blood group A and B antigens was mediated by Lam29 that is a putative component of ABC transporter as an adhesin-like protein. Lactobacillus mucosae ME-340 expressing Lam29 may be useful for competitive exclusion of pathogens via blood group antigen receptors in the human gastrointestinal mucosa and in the development of new probiotic foods.