Table 3.

Effects of C0–C2 binding on the FRET efficiency of donor-acceptor labeled F-actin

Data represent mean ± S.E. (n > 4). The positive control (actin induced to bundle with 20 mm MgCl₂ (0+Mg*)) shows the expected high FRET efficiency (∼35%), calculated from fluorescent lifetimes of donor-only τ_D and donor-acceptor τ_DA (Equation 6). In contrast, binding of 0–40 μm C0–C2 caused very little change in FRET efficiency (∼3–5%) as compared to actin alone (∼2%).

C0–C2 added	FRET efficiency
μm	E
0	1.5 ± 0.1
0+Mg*	34.9 ± 0.1
5	2.7 ± 0.2
10	3.7 ± 0.1
20	5.3 ± 0.1
40	4.4 ± 0.3