Monocyte Nonspecific Esterase: Purification and Subunit Structure

Monocyte nonspecific esterase has been purified from cultured cells of the acute myeloid leukemia cell line. ML-l. The purified enzyme shows the characteristic properties of the monocyte neutral serine carboxyI esterase, with high sensitivity to organophosphorus inhibitors and sodium fluoride inhibitor. The enzyme is a membrane protein which in the native state exists as a monomer of a mol wt of -68,000 and a trimer of mol wt 205,000. These forms exhibit a complex pattern of dissociation and reassociation based on apparent noncovalent binding of subunits. The delipidated dissociated enzyme runs as a single protein