A hemagglutinin specific for sialic acids in a rat brain synaptic vesicle-enriched fraction.
A hemagglutinating activity was detected in a synaptic vesicle-enriched fraction prepared from adult rat brain, using trypsinized glutaraldehyde-fixed rabbit erythrocytes. The specific activity of the fraction, in two series of experiments, was 7.5 and 16-fold higher than in the other subcellular fractions. The activity was absent from the synaptosome cytosol. In a study using twenty-five different carbohydrates and glycoproteins, best inhibitors were N-acetylneuraminic acid and N-glycolylneuraminic acid, together with bovine submaxillary mucin and a glycopeptide fraction prepared from rabbit erythrocyte membranes. The activity was thermolabile and very sensitive to proteolytic enzymes (but insensitive to neuraminidase) indicating that a protein (agglutinin) is responsible for the activity. Experiments using detergents and high ionic strength showed that the agglutinin is tightly bound to membranes, inactivated by the so-called non denaturing detergents, and stable in diluted sodium dodecyl sulphate. Hypotheses are discussed on the possible function of the agglutinin.
Popoli
M
M
Department of Neurology, Second School of Medicine, Napoli, Italy.
Mengano
A
A
D000818:Animals; D002540:Cerebral Cortex / Q000276:immunology*; D005260:Female; D006388:Hemagglutinins / Q000032:analysis*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012794:Sialic Acids / Q000276:immunology*; D013572:Synaptic Vesicles / Q000276:immunology*
D006388:Hemagglutinins; D012794:Sialic Acids