JCI - Surfactant proteins A and D inhibit the growth of Gram-negative bacteria by increasing membrane permeability

Surfactant proteins A and D inhibit the growth of Gram-negative bacteria by increasing membrane permeability

Huixing Wu, Alexander Kuzmenko, Sijue Wan, Lyndsay Schaffer, Alison Weiss, James H. Fisher, Kwang Sik Kim, Francis X. McCormack

Published in Volume 111, Issue 10

J Clin Invest. 2003; 111(10):1589–1602 doi:10.1172/JCI16889

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Figure 5

Attenuation 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.