BIOCHEMICAL-COMPARISON OF BRAIN GLYCOSAMINOGLYCANS BETWEEN NORMAL ANDREELER MUTANT MICE

Glycosaminoglycans (GAGs) were isolated from the brains of reeler and normal mice on postnatal days 13 and 20. The GAG content of the reeler mouse brain, based upon the amount of DNA, was about 150% that of the normal mouse brain on both days. The GAGs consisted of chondroitin su lfate (CS), heparan sulfate (HS), hyaluronic acid (HA) and polysialosy l glycopeptides. There was no significant difference in the compositio n of GAGs isolated from either reeler or normal brain. Repeating disac charide compositions of CS and HS were also similar in reeler and norm al brains. Core proteins of brain chondroitin sulfate proteoglycans (C SPGs), solubilized with phosphate buffered saline, were prepared by di gesting purified CSPGs with chondroitinase ABC, and were analyzed by S DS-polyacrylamide slab gel electrophoresis. There was no difference in the composition of core proteins from either reeler or normal brain. These results indicate that, although the GAG content of the reeler mo use brain is higher than the normal, all structural parameters of GAGs /CSPGs so far examined were normal. The rate of synthesis and/or degra dation of brain GAGs may be affected in the mutant mouse brain.