Pediatric Infections Research Center (PIRC), Research Institute for Children Health, Shahid Beheshti University of Medical Sciences, Tehran 1546815514, Iran.
Skin Research Center, Shahid Beheshti University of Medical Sciences, Tehran 1989934148, Iran.
Biomolecules. 2018 Oct 22;8(4):118. doi: 10.3390/biom8040118.
The emergence of antimicrobial resistance among pathogenic microorganisms has been led to an urgent need for antibiotic alternatives. Antimicrobial peptides (AMPs) have been introduced as promising therapeutic agents because of their remarkable potentials. A new modified cathelicidin-BF peptide (Cath-A) with 34 amino acid sequences, represents the potential antimicrobial effects against methicillin-resistant (MRSA) with slight hemolytic and cytotoxic activities on eukaryotic cells. In this study, the effects of Cath-A on , and isolated from medical instruments were studied. Cath-A inhibited the growth of bacterial cells in the range of 8⁻16 μg/mL and 16-≥256 μg/mL for and , respectively. The peptide significantly removed the established biofilms. To display a representative approach for the cost-effective constructions of peptides, the recombinant Cath-A was cloned in the expression vector pET-32a(+) and transformed to . The peptide was expressed with a thioredoxin (Trx) sequence in optimum conditions. The recombinant peptide was purified with a Ni affinity chromatography and the mature peptide was released after removing the Trx fusion protein with enterokinase. The final concentration of the partially purified peptide was 17.6 mg/L of a bacterial culture which exhibited antimicrobial activities. The current expression and purification method displayed a fast and effective system to finally produce active Cath-A for further in-vitro study usage.
抗药性微生物的出现导致对抗生素替代品的迫切需求。由于具有显著的潜力,抗菌肽 (AMPs) 已被引入作为有前途的治疗剂。一种新的 34 个氨基酸序列的改良抗菌肽 (Cath-A),代表了对耐甲氧西林金黄色葡萄球菌 (MRSA) 的潜在抗菌作用,对真核细胞仅有轻微的溶血和细胞毒性。在这项研究中,研究了 Cath-A 对 和 从医疗器械中分离出的 的影响。Cath-A 抑制细菌细胞的生长范围为 8⁻16 μg/mL 和 16-≥256 μg/mL,分别为 和 。该肽显著去除了已建立的生物膜。为了展示一种具有成本效益的肽构建代表性方法,将重组 Cath-A 克隆到表达载体 pET-32a(+)中,并转化为 。在最佳条件下,该肽以硫氧还蛋白 (Trx) 序列表达。用镍亲和层析纯化重组肽,用肠激酶去除 Trx 融合蛋白后释放成熟肽。部分纯化肽的最终浓度为 17.6 mg/L 的细菌培养物,具有抗菌活性。当前的表达和纯化方法展示了一种快速有效的系统,最终产生了活性 Cath-A,用于进一步的体外研究使用。