Before revision:  Theory of polymer brushes and models of side-chain-induced internal tension show our data are consistent with a polydisperse aggrecan population, attributable to varying degrees of glycosylation  .
After revision:  Theory of polymer brushes and models of side-chain-induced internal tension show our data are consistent with a polydisperse aggrecan population, attributable to varying degrees of glycosylation . By enzymatically deglycosylating aggrecan, we show that aggrecan glycosylation is the structural feature which causes HA stiffening. We then construct a simple stochastic binding model to show that variable glycosylation leads to a wide distribution of internal tensions in HA, causing variations in the mechanics at much longer length-scales .