SEC-MALS analysis of PilB N-terminal fragments and their complexes with PilZ.
A 0.1 ml protein sample (3.0 mg/ml– 4 mg/mL) was separated by passage through a Superdex 200 column (S200 10/300, GE) coupled to a multi-angle light scattering system and refractive index detector. Protein elution was monitored at 280 nm (continuous line). Open circles indicate the calculated molecular mass distributions. The following measured molecular weights (MW) were calculated: A) PilB1-190 = 22 kDa (20 kDa MWtheoretical), B) PilB12-163 = 17 kDa (17 kDa MWtheoretical), C) PilB1-190-PilZ complex = 33 kDa (33 kDa MWtheoretical) and D) PilB12-163-PilZ complex = 30 kDa (29 kDa MWtheoretical).