Biological activity of a proteoglycan form of macrophage colony-stimulating factor and its binding to type V collagen.
Two different types of macrophage colony-stimulating factors (M-CSF) were found, one with an apparent molecular mass of 85 kDa and the other greater than 200 kDa. The high molecular mass M-CSF was identified as a proteoglycan carrying chondroitin sulfate glycosaminoglycan and was designated as the proteoglycan form of M-CSF (PG-M-CSF). In this study, we compared the biological activity of the 85-kDa M-CSF and PG-M-CSF and examined the binding properties of these two M-CSF to certain extracellular matrix proteins, i.e. types I-V collagen and fibronectin, using a modified enzyme-linked immunosorbent assay. PG-M-CSF was capable of supporting the formation of murine macrophage colonies, and pretreatment of PG-M-CSF with chondroitinase AC, which degrades chondroitin sulfate, did not alter its colony-stimulating activity. The specific activity of PG-M-CSF was similar to that of the 85-kDa M-CSF. The 85-kDa M-CSF had no apparent affinity for the extracellular matrix proteins examined, whereas PG-M-CSF had an appreciable binding capacity to type V collagen, but did not bind to types I, II, III, and IV collagen or to fibronectin. Pretreatment of PG-M-CSF with chondroitinase AC completely abolished the binding of the species to type V collagen. Addition of exogenous chondroitin sulfate inhibited the binding of PG-M-CSF to type V collagen in a dose-dependent manner. These data indicated that the interaction between PG-M-CSF and type V collagen was mediated by the chondroitin sulfate chain of PG-M-CSF. PG-M-CSF bound to type V collagen could stimulate the proliferation of bone marrow macrophages, indicating that the matrix protein-bound PG-M-CSF retained its biological activity. This interaction between PG-M-CSF and type V collagen implies that the role of PG-M-CSF may be distinct from that of 85-kDa M-CSF.
Suzu
S
S
Biochemical Research Laboratory, Morinaga Milk Industry Co, Ltd., Kanagawa, Japan.
Ohtsuki
T
T
Makishima
M
M
Yanai
N
N
Kawashima
T
T
Nagata
N
N
Motoyoshi
K
K
D000818:Animals; D001854:Bone Marrow Cells; D016466:CHO Cells; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000378:metabolism*; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay; D007700:Kinetics; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism* / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology* / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D011509:Proteoglycans / Q000378:metabolism* / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D013552:Swine
D011509:Proteoglycans; D011994:Recombinant Proteins; D016173:Macrophage Colony-Stimulating Factor; D003094:Collagen