Figure 1
From: Antimicrobial activity of a C-terminal peptide from human extracellular superoxide dismutase
Activities of selected peptides. (A) Antimicrobial activity of RQA21 and LL37 peptides (at 100 μM in RDA) against the indicated microbes. Bacteria (4 × 106 cfu) or C. albicans ATCC 90028 (1 × 105) was inoculated in 0.1% TSB agarose gel. The zones of clearance correspond to the inhibitory effect of each peptide (6 μl at 100 μM) after incubation at 37°C for 18–24 h (mean values are presented, n = 3). (B) 2 × 106 colony-forming units/ml of E. coli 37.4 bacteria were incubated in 50 μl with peptides at 30 and 60 μM for 2 hours followed by plating on TSB agar plates and cfu were determined. Upper panel; in 10 mM Tris, pH 7.4, 5 mM glucose, lower panel; the same buffer with 0.15 M NaCl. (C) Antimicrobial activity of RQA21 and LL37 peptides (at 100 μM in RDA) against E. coli 37.4 in the presence of citrate plasma at the indicated concentrations. (D) Left panel; Analysis of hemolytic effects of RQA21 peptide and comparison with LL-37. The cells were incubated with peptides at the indicated concentrations (x-axis). 2% Triton X-100 (Sigma-Aldrich) served as positive control. The absorbance of hemoglobin release was measured at λ 550 nm and is expressed as % of Triton X-100 induced hemolysis (y-axis) (n = 3, mean values and SD is indicated). Right panel; HaCaT keratinocytes were subjected to RQA21 and LL-37. Cell permeabilizing effects were measured by the LDH based TOX-7 kit.