Fig. 4.

CK-666 and CK-869 significantly decrease the sedimentation rate of the GST-VCA₂:actin₂:Arp2/3 complex in sedimentation velocity analytical ultracentrifugation experiments. (A) Sedimentation coefficient distribution for three sedimentation velocity runs containing 1 μM BtArp2/3 complex with or without 10 μM GST-VCA or 10 μM GST-VCA plus 10 μM actin with 20 μM latrunculin B. (B) Tabulation of sedimentation coefficients and molecular weights (exp = experimentally calculated; seq = calculated from sequence) for peaks observed in experiments in (A). (C, E-F). Sedimentation coefficient distribution of 1 μM BtArp2/3 complex alone (E), with 10μM GST-VCA (F), or with 10 μM GST-VCA, 10 μM actin and 20 μM latrunculin (C) in the presence or absence of CK-666 or CK-869. (D) Plot of sedimentation coefficient versus inhibitor concentration for a range of concentrations of CK-666 or CK-869. (G) Sedimentation coefficient distributions for three sedimentation velocity runs monitored by absorbance at 491 nm containing 1 μM BtArp2/3 complex, 10 μM GST-VCA, 10 μM 70% labeled OG-actin, 20 μM latrunculin B with or without 150 μM CK-666 or CK-869. Integrated peak areas averaged from three separate runs are reported, along with the ratio of the fast sedimenting species compared to the total.