A–F. Reactions were Latrunculin B/phalloidin arrested 60 seconds after mixing, fractionated and analyzed as described. Conditions: 5.8 µm ActA-coated beads mixed with 3 µM actin (5% TMR-labeled), and Arp2/3 and CP as indicated.
A. Representative shells after arrest, fractionation, and washing.
B. Shell thickness decreases with [Arp2/3] and increases with [CP]. Error bars represent standard deviation (average n=17).
C. Soluble actin concentration at the time of arrest decreases with increasing [CP].
D. Total amount of actin in the shells does not vary with [Arp2/3] or [CP].
E. Average actin density in the shells increases with [Arp2/3] and decreases with [CP]. Density was calculated by dividing the actin mass in (D) by the volume of the shells as derived from (B).
F. Total number filaments in the shells is independent of [Arp2/3] but increases with [CP].