Fig. 1.

MSAs exhibit distinct effects on 2-m-AzTax photoaffinity labeling of β-tubulin from bovine brain and chicken erythrocytes. Four micromolars soluble BBT or CET were incubated with 5 µM [³H]2-m-AzTax and 1 mM GTP, in the absence or presence of a fourfold molar excess of MSAs, followed by UV irradiation as described in Materials and Methods. (A) Analysis by 9% SDS/PAGE and fluorography. Tax: Taxol. (B) Each band in A was image quantified by ImageJ. Results from three to four experiments are presented as mean ± SE. C, control.