Adhesion of A5 (A) and VNRC3 (B) cells to immobilized echistatin and its analogues. Five micrograms per sample of echistatin (a), 5 μg per sample of D27W echistatin (b), 4 μg per sample of echistatin 1-41 (c), and 5 μg per sample of R24A echistatin (d) were immobilized overnight at 4°C on a 96-well plate (Costar) in carbonate/bicarbonate buffer, pH 9.2. After blocking, the CMFDA-labeled cells were added to each well and incubated as described in the Materials and Methods. Adhesion of CHO-K1 cells was negligible and at the level of nonspecific adhesion of transfected cells to bovine serum albumin. Error bars represent the standard deviations from three independent experiments.