Characterization of macrophage colony-stimulating factor in body fluids by immunoblot analysis.
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.
Suzu
S
S
Biochemical Research Laboratory, Morinaga Milk Industry Co, Ltd, Kanagawa, Japan.
Yanai
N
N
Sato-Somoto
Y
Y
Yamada
M
M
Kawashima
T
T
Hanamura
T
T
Nagata
N
N
Takaku
F
F
Motoyoshi
K
K
D001826:Body Fluids / Q000737:chemistry*; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000032:analysis; D007938:Leukemia / Q000097:blood / Q000652:urine; D016173:Macrophage Colony-Stimulating Factor / Q000032:analysis* / Q000737:chemistry; D008970:Molecular Weight; D011247:Pregnancy
D007074:Immunoglobulin G; D016173:Macrophage Colony-Stimulating Factor