Antifungal effects of the D5-derived and the modified peptides. (a)–(e) The D5-derived peptides HKH20, GKH17, and modified variants of GKH17 were tested against C. parapsilosis ATCC 90018 in viable count assays at different physiological conditions. Candida cells were subjected to 30 μM of the peptides at (a) low salt conditions (10 mM Tris, pH 7.4), (b) physiological salt conditions (0.15 M NaCl in 10 mM Tris, pH 7.4), (c) in presence of 20% human plasma (0.15 M NaCl, 10 mM Tris, pH 7.4), (d) in presence of 50% human plasma (0.15 M NaCl, 10 mM Tris, pH 7.4), and (e) in presence of 50% human serum (0.15 M NaCl, 10 mM Tris, pH 7.4). Most of the antifungal activities of the D5-derived peptides HKH20 and GKH17 were lost, whereas the activities of the modified variants of GKH17 peptides were retained in physiological salt and presence of human plasma or serum. Data represents the mean ± (SD) of triplicate determinations from a single experiment representative of at least two experiments.