Alpha 2-macroglobulin is an astroglia-derived neurite-promoting factor for cultured neurons from rat central nervous system.
The neurite promoting factors in the astroglial conditioned medium (As-CM) were characterized by using primary cultures of embryonic rat neocortical neurons. The factors in the As-CM bind to lectins such as wheat germ agglutinin (WGA), suggesting that they contain sugar moieties. When the WGA-bound fractions were applied on a Superose 6 column, the activity was recovered mainly in two fractions, peak I and peak II. The peak II fraction was further purified by Mono Q anion exchange chromatography. A single protein band of 180 kDa was detected in the final Mono Q fraction by sodium dodecylsulfate polyacrylamide gel electrophoresis. The molecular weight coincided with that of alpha 2-macroglobulin (alpha 2M). Western blotting showed that the single protein band was reacted with anti-alpha 2M antibody but not with anti-fibronectin and anti-laminin antisera. The neurite-promoting activity of the Mono Q fraction was inhibited by anti-alpha 2M antibody. Furthermore, commercially available alpha 2M also promotes neurite outgrowth in our assay system. These results strongly suggested that alpha 2M is one of the neurite-promoting factors in the As-CM.
Mori
T
T
Biochemistry Section, Asahi Breweries, Ltd., Tokyo, Japan.
Iijima
N
N
Kitabatake
K
K
Kohsaka
S
S
D000818:Animals; D001253:Astrocytes / Q000737:chemistry*; D001369:Axons / Q000502:physiology; D015153:Blotting, Western; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000737:chemistry* / Q000166:cytology; D004591:Electrophoresis, Polyacrylamide Gel; D009414:Nerve Growth Factors / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D009474:Neurons / Q000648:ultrastructure*; D051381:Rats; D000511:alpha-Macroglobulins / Q000302:isolation & purification / Q000502:physiology*
D009414:Nerve Growth Factors; D000511:alpha-Macroglobulins