Characterization of macrophage colony-stimulating factor in body fluids by
immunoblot analysis
S Suzu, N Yanai, Y Sato-Somoto, M Yamada, T Kawashima, T Hanamura, N Nagata, F Takaku and K Motoyoshi
Biochemical Research Laboratory, Morinaga Milk Industry Co, Ltd, Kanagawa,
Japan.
We characterized the molecular species of human macrophage colony-
stimulating factor (hM-CSF) found in serum and urine, using immunoblot
analysis after partial purification on an antibody-bound affinity column.
Although antibodies were prepared using the recombinant product of the
large form of hM-CSF with a molecular weight (MW) of 85 Kd as the antigen,
this immunoblot system was also capable of detecting the small form of
hM-CSF with a MW of 40 to 60 Kd. A single band with a MW of 43 Kd, which
reacted with anti-recombinant hM-CSF IgG but not with control IgG, was
found when serum and urine from normal adults underwent electrophoresis on
reduced sodium dodecyl sulfate- polyacrylamide gel and subsequent
immunoblotting. This band represented a subunit of the large form of
hM-CSF, because the large form of hM-CSF is a homodimer of a subunit with a
MW of 43 Kd and the small form of hM- CSF is a homodimer of a subunit with
a MW of 20 to 30 Kd. Analysis of serum and urine from leukemic patients and
pregnant women, who had higher serum levels of hM-CSF than normal adults,
showed only a single band with a MW of 43 Kd as a hM-CSF-specific molecule.
These results suggest that the large form of hM-CSF is the major species in
human body fluids.
Volume 77,
Issue 10,
pp. 2160-2165,
05/15/1991
Copyright © 1991 by The American Society of Hematology
