Antimicrobial Peptide GL13K Is Effective in Reducing Biofilms of Pseudomonas aeruginosa
Antimicrobial Peptide GL13K Is Effective in Reducing Biofilms of Pseudomonas aeruginosa
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DOI：
10.1128/aac.00311-13
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发表时间：
2013-10-01
影响因子：
4.9
通讯作者：
Gorr, Sven-Ulrik
中科院分区：
文献类型：
--
作者：
Hirt, Helmut;Gorr, Sven-Ulrik
人腮腺分泌蛋白（PSP; BPIF 2A）被预测为在结构上类似于杀菌/渗透性增加蛋白和脂多糖（LPS）结合蛋白。基于已知的抗菌肽在后两种蛋白质中的位置，鉴定了PSP序列中的潜在活性肽。一种这样的肽GL 13 NH 2（PSP残基141至153）先前显示干扰LPS结合并凝集细菌而没有杀菌活性。通过引入三个额外的带正电荷的赖氨酸残基，该肽被转化为新的杀菌阳离子肽GL 13 K（对铜绿假单胞菌的MIC，8 μ g/ml [5.6 μ M]）。我们研究了GL 13 K对铜绿假单胞菌PAO 1的静态单种生物膜的生物膜活性。将24小时生物膜暴露于64 μ g/ml（44.8 μ M）GL 13 K两小时可使生物膜细菌减少102，100 μ g/ml（70 μ M）GL 13 K可使细菌减少10（3）。在48小时的生物膜上可以实现类似的结果。较低浓度的GL 13 K（32 μ g/ml [22.4 μ M]）与妥布霉素联合使用，成功减少了生物膜细胞数。该组合治疗还在大多数（67.5%）测试样品中实现了生物膜的完全根除。GL 13 K的丙氨酸扫描揭示了肽序列的位置6中的亮氨酸残基的重要性，其中替换导致膜活性的损失，而替换带电残基的影响不太明显。发现细菌金属蛋白酶部分地修饰GL 13 K，但不修饰肽的D氨基酸形式。
Human parotid secretory protein (PSP; BPIF2A) is predicted to be structurally similar to bactericidal/permeability-increasing protein and lipopolysaccharide (LPS)-binding protein. Based on the locations of known antimicrobial peptides in the latter two proteins, potential active peptides in the PSP sequence were identified. One such peptide, GL13NH2 (PSP residues 141 to 153) was shown previously to interfere with LPS binding and agglutinate bacteria without bactericidal activity. By introducing three additional positively charged lysine residues, the peptide was converted to the novel bactericidal cationic peptide GL13K (MIC for Pseudomonas aeruginosa, 8 mu g/ml [5.6 mu M]). We investigated the antibiofilm activity of GL13K against static, monospecies biofilms of P. aeruginosa PAO1. Two-hour exposure of a 24-h biofilm to 64 mu g/ml (44.8 mu M) GL13K reduced biofilm bacteria by 102, and 100 mu g/ml (70 mu M) GL13K reduced bacteria by 10(3). Similar results could be achieved on 48-h-old biofilms. Lower concentrations of GL13K (32 mu g/ml [22.4 mu M]) were successful in reducing biofilm cell numbers in combination with tobramycin. This combination treatment also achieved total eradication of the biofilm in a majority (67.5%) of tested samples. An alanine scan of GL13K revealed the importance of the leucine residue in position six of the peptide sequence, where replacement led to a loss of antibiofilm activity, whereas the impact of replacing charged residues was less pronounced. Bacterial metalloproteases were found to partially inactivate GL13K but not a D amino acid version of the peptide.