Spastin's Microtubule-Binding Properties and Comparison to Katanin
Panel A shows a SDS-gel of co-sedimentation assays with spastin (E442Q mutant, 1 mM ATP) and a constant concentration of microtubules (1 µM; indicated by a dotted line). With increasing spastin concentrations, an increasing amount of protein is co-sedimented with microtubules. Panel B: Densitometric analysis allowed plotting of the spastin concentrations bound to microtubules against free spastin concentrations. The horizontal dotted line indicates the concentration of tubulin used in the assays. The diagonal dashed lines connect points with the same total concentration of spastin. The concentrations increase towards the upper right. Steeper curves reflect a higher affinity. Panel C shows the same experiment for wild type spastin.