Steric exclusion of cells

摘要: Abstract The mechanism by which chondroitin sulfate enhances both the self-aggregation and concanavalin A (ConA)-induced agglutination of trypsin-dissociated embryonic chick retina cells was investigated. Studies with fluorescently labeled ConA showed no influence on patching or capping. When 3H- 35SO4-labeled glycosaminoglycans proteoglycans from retinas were added to freshly dissociated cells, an average less than 2% label became associated unwashed cell pellet, most this removed a single wash. presence did not alter amount binding criterion. Rapid aggregation in absence promoted number natural synthetic polymers. Aggregation rate bore direct relationship polymer viscosity at low viscosities inhibited high viscosities, apparently due reduced collision frequency. For any given polymer, directly related its molecular weight concentration. Linear polymers more effective branched ones. Neutral as those strongly polyanionic. Stable aggregates formalin-fixed All these observations are consistent hypothesis that enhancement physiological concentrations is largely steric exclusion mesh. Although others have shown probably interact specifically some evidence presented here suggests macromolecules virtue their excluded volumes could also important non-specific influences migration reorganization during morphogenesis.