Figure 4. A minor-groove binder competing with tau protein in binding to DNA.

Conditions were as described in Figure 1, except 26 bp dsDNA was used with the addition of distamycin A, a minor groove binder (A). The DNA was mixed with tau protein at different quantitative ratios as indicated. Distamycin A at different concentrations (quantitative ratios as indicated) was added to the tau-DNA complex (B). DNA in the presence of distamycin A at different concentrations was used as a control (C). M represents molecular mass marker.