Binds bacterial lipopolysaccharide (LPS) (PubMed:17569869, PubMed:17803912). Cooperates with TLR4 in the innate immune response to bacterial lipopolysaccharide (LPS), and with TLR2 in the response to cell wall components from Gram-positive and Gram-negative bacteria (PubMed:11160242, PubMed:11593030). Enhances TLR4-dependent activation of NF-kappa-B (PubMed:10359581). Cells expressing both LY96 and TLR4, but not TLR4 alone, respond to LPS (PubMed:10359581).