Figure 6.

Hydrodynamic analysis of T701-Myo1c A, measurement of Stokes radius using gel filtration. Globular standards were used to calibrate the column, and retention times were converted to Stokes radius (inset). T701-Myo1c was separated at 25°C in the presence of 100 μM EGTA (Stokes radius of 4.8 nm) or 25 μM CaCl₂ (3.9 nm). B-D, measurement of sedimentation coefficients using sucrose-gradient centrifugation. Size standards were used to calibrate the gradient, and fraction numbers were converted to sedimentation coefficient (inset, panel B). T701-Myo1c concentration was determined by ELISA. B, T701-Myo1c sedimentation at 4°C in the presence of 100 μM EGTA (3.9 S) or 25 μM CaCl₂ (3.5 S). C, T701-Myo1c sedimentation in the presence of EGTA at 25°C, with (4.6 S) or without (3.8 S) the continuous presence of 5 μM calmodulin (+CaM). D, T701-Myo1c sedimentation in the presence of 25 μM CaCl₂ at 25°C, with (3.9 S) or without (3.1 S) the continuous presence of 5 μM calmodulin.