Surfactant proteins A and D inhibit the growth of Gram-negative bacteria by increasing membrane permeability
J. Clin. Invest. Huixing Wu, et al. 111:1589 doi:10.1172/JCI16889 [
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Figure 5Attenuation of
E. coli K12–induced light scattering by SP-A and SP-D. (
a)
E. coli K12 were mixed with 25 μg/ml (open squares) or 250 μg/ml (open triangles) hSP-A or no protein (open circles) and incubated in LB at 37°C in a shaking water bath. Bacterial density was monitored by absorbance at 400 nm. (
b)
E. coli grown as above were incubated with hSP-A (filled circles), 300 μg/ml J5 LPS (open circles), 300 μg/ml J5 LPS plus 100 μg/ml hSP-A (open triangles), or no additives (x’s). (
c)
E. coli grown as above were incubated with 100 μg/ml rmSP-D (open squares), 300 μg/ml J5 LPS (open triangles), or 300 μg/ml J5 LPS plus 100 μg/ml rmSP-D (filled circles). Data are mean ± SEM;
n = 3. (
d) Bacterial aggregation was assessed under the light microscope after incubation of
E. coli K12 with hSP-A, rSP-A, rrSP-A, a C-terminal fragment of SP-A containing residues A81–F228 (ΔSP-A), rSP-D, rmSP-D, a C-terminal fragment of SP-D containing residues D203–F355 (ΔSP-D), or BSA, and viewed with the light microscope.
