Removes the secondary (acyloxyacyl-linked) fatty acyl chains from the lipid A region of bacterial lipopolysaccharides (LPS). By breaking down LPS, terminates the host response to bacterial infection and prevents prolonged and damaging inflammatory responses. In peritoneal macrophages, seems to be important for recovery from a state of immune tolerance following infection by Gram-negative bacteria. 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. 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.