Effect of cytochalasin D on conformation of Fn-D/A in matrix fibrils.
(A) Fluorescence image of fibril after treatment of
cells with 10 μM cytoD for 1 h after incorporation of Fn-D/A
into fibrils. Fibrils in cell samples treated with cytoD appeared
predominantly yellow, indicating a higher level of FRET than in the
predominantly green fibrils of untreated samples. The increase in FRET
indicated that cytoD allowed refolding of Fn-D/A in fibrils relative
to untreated samples. (Scale bar, 10 μm.) (B) The mean
level of FRET (acceptor peak divided by donor peak) from fibrils in
untreated samples, 54% ± 10% (n = 115, 11
fibrils), was significantly lower than in samples treated with cytoD,
62 ± 3.3% (n = 78,8 fibrils)
(P < 0.001, two-sample t test). The
range of FRET in fibrils of cytoD-treated cells (15%) was also
narrower than that of untreated cells (45%).