Sánchez-Vásquez Lorenzo, Silva-Sanchez Jesus, Jiménez-Vargas Juana Maria, Rodríguez-Romero Adela, Muñoz-Garay Carlos, Rodríguez Maria C, Gurrola Georgina B, Possani Lourival D
Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autonóma de México, Avenida Universidad, México.
Biochim Biophys Acta. 2013 Jun;1830(6):3427-36. doi: 10.1016/j.bbagen.2013.01.028. Epub 2013 Feb 9.
Microbial antibiotic resistance is a challenging medical problem nowadays. Two scorpion peptides displaying antibiotic activity: hadrurin and vejovine were taken as models for the design of novel shorter peptides with similar activity.
Using the standard Fmoc-based solid phase synthesis technique of Merrifield twelve peptides (18 to 29 amino acids long) were synthesized, purified and assayed against a variety of multi-drug resistant Gram-negative bacteria from clinical isolates. Hemolytic and antiparasitic activities of the peptides and their possible interactions with eukaryotic cells were verified. Release of the fluorophore calcein from liposomes treated with these peptides was measured.
A peptide with sequence GILKTIKSIASKVANTVQKLKRKAKNAVA), and three analogs: Δ(Α29), Δ(K12-Q18; Ν26-Α29), and K4N Δ(K12-Q18; Ν26-Α29) were shown to inhibit the growth of Gram-negative (E. coli ATCC25922) and Gram-positive bacteria (S. aureus), as well as multi-drug resistant (MDR) clinical isolated. The antibacterial and antiparasitic activities were found with peptides at 0.78 to 25μM and 5 to 25μM concentration, respectively. These peptides have low cytotoxic and hemolytic activities at concentrations significantly exceeding their minimum inhibitory concentrations (MICs), showing values between 40 and 900μM for their EC50, compared to the parent peptides vejovine and hadrurin that at the same concentration of their MICs lysed more than 50% of human erythrocytes cells.
These peptides promise to be good candidates to combat infections caused by Gram-negative bacteria from nosocomial infections.
Our results confirm that well designed synthetic peptides can be an alternative for solving the lack of effective antibiotics to control bacterial infections.
微生物抗生素耐药性是当今一个具有挑战性的医学问题。两种具有抗生素活性的蝎肽：hadrurin和vejovine被用作设计具有相似活性的新型短肽的模型。
采用Merrifield基于Fmoc的标准固相合成技术合成了12种肽（18至29个氨基酸长），对其进行纯化并针对来自临床分离株的多种耐多药革兰氏阴性菌进行检测。验证了这些肽的溶血和抗寄生虫活性以及它们与真核细胞的可能相互作用。测量了用这些肽处理的脂质体中荧光素钙黄绿素的释放。
序列为GILKTIKSIASKVANTVQKLKRKAKNAVA的一种肽以及三种类似物：Δ(A29)、Δ(K12-Q18;N26-A29)和K4N Δ(K12-Q18;N26-A29)显示出对革兰氏阴性菌（大肠杆菌ATCC25922）和革兰氏阳性菌（金黄色葡萄球菌）以及耐多药（MDR）临床分离株生长的抑制作用。分别在0.78至25μM和5至25μM浓度下发现这些肽具有抗菌和抗寄生虫活性。这些肽在浓度显著超过其最低抑菌浓度（MIC）时具有低细胞毒性和溶血活性，其半数有效浓度（EC50）值在40至900μM之间，相比之下，亲本肽vejovine和hadrurin在相同MIC浓度下会使超过50%的人红细胞裂解。
这些肽有望成为对抗医院感染中革兰氏阴性菌引起的感染的良好候选药物。
我们的结果证实，精心设计的合成肽可以作为解决缺乏有效抗生素来控制细菌感染问题的一种替代方法。
