Estimation of the mass of the HAF-1 complex. EMSA was performed as described in Materials and Methods, using the −68 to −30 bp gp91^phox promoter probe and nuclear extract isolated from PLB985 cells. Furguson plot calculations were performed as described in Materials and Methods. (A) The mobility response slopes for each species, plotted as relative mobility (Rf) versus acrylamide concentration. Protein standards are as follows: (•) carbonic anhydrase (29 kD); (○) ovalbumin (45 kD); (×) bovine serum albumin (66 kD); (▪) bovine serum albumin dimer (132 kD); (□) alcohol dehydrogenase (150 kD); (▴) -amylase (200 kD). (▵) denotes the behavior of the HAF-1 complex. (B) The Furguson plot of the mobility response slopes presented in (A) versus mass. (•) The protein standards; (○) the HAF-1 complex.