Human acyloxyacyl hydrolase is an unusual lipase, found in phagocytic cells
, that removes acyl chains from bacterial lipopolysaccharides (LPS) and gly
cerolipids. It is a heterodimer in which two glycosylated peptides are link
ed by disulfide bonding. The large subunit contains the active site serine,
while the smaller subunit has striking sequence similarity to the saposins
, peptide cofactors for several sphingolipid hydrolases. Since rabbits and
mice are widely used for studies of LPS-animal interactions, we asked if mu
rine and lapine AOAHs resemble the human enzyme. We report here that murine
and lapine AOAHs share the distinctive features of the human AOAH primary
sequence and have similar affinity for LPS. The structure of this unusual l
ipase appears to have been highly conserved.