Removes the secondary (acyloxyacyl-linked) fatty acyl chains from the lipid A region of bacterial lipopolysaccharides (PubMed:1883828, PubMed:8089145, PubMed:29343645). By breaking down LPS, terminates the host response to bacterial infection and prevents prolonged and damaging inflammatory responses (By similarity). In peritoneal macrophages, seems to be important for recovery from a state of immune tolerance following infection by Gram-negative bacteria (By similarity). a 3-(acyloxy)acyl derivative of bacterial toxin + H2O = 3-hydroxyacyl derivative of bacterial toxin + a fatty acid + H(+) Binds 3 Ca(2+) ions per subunit. The calcium ions probably have a structural role. Inhibited by EDTA. Heterodimer of the large and small subunits; disulfide-linked. Detected in urine. Cleaved into a large and a small subunit. The small subunit is N-glycosylated.