FIGURE 3.

Effect of surfactant protein SP-B on the morphology of small nanometer-sized condensed nanodomains into the LE regions of DPPC films. Micrographs show SFM scans of 1 × 1 μm areas of DPPC monolayers containing the indicated protein percents by weight, compressed to 11 mN/m and transferred to mica supports. Marked are examples of small Euclidian round nanodomains (red-colored) and large branched fractal domains (blue-colored). (a) Effect of SP-B on the height of condensed nanodomains over expanded nano-areas of the films. (b) Effect of the protein on the percent of surface in the films occupied by total condensed area (closed squares) and small nanometer-sized condensed nanodomains (closed circles). (c) Effect of protein on the total area/perimeter ratio of the surface occupied by condensed nanodomains.