Monocyte nonspecific esterase: purification and subunit structure
J Yourno
Monocyte nonspecific esterase has been purified from cultured cells of the
acute myeloid leukemia cell line, ML-1. The purified enzyme shows the
characteristic properties of the monocyte neutral serine carboxyl 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 approximately 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 chain of a mol wt
of approximately 62,000 on sodium dodecyl sulfate (SDS) gel
electrophoresis. The relation of the subunits to monocyte isoenzymes seen
on isoelectric focusing (IEF) and polyacrylamide gel electrophoresis at pH
9.5 (pH 9.5 PAGE) of cell extracts is demonstrated. Availability of
purified enzyme allows development of monoclonal antibodies and analysis of
myeloid differentiation. In addition, the substrate specificity and
function of the purified monocyte ectoenzyme are being examined.
Volume 68,
Issue 2,
pp. 479-487,
08/01/1986
Copyright © 1986 by The American Society of Hematology
