Lim Jeong-A, Shin Hakdong, Heu Sunggi, Ryu Sangryeol
Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Agricultural Biomaterials and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea.
J Microbiol Biotechnol. 2014 Jun 28;24(6):803-11. doi: 10.4014/jmb.1403.03035.
Concerns over drug-resistant bacteria have stimulated interest in developing alternative methods to control bacterial infections. Endolysin, a phage-encoded enzyme that breaks down bacterial peptidoglycan at the terminal stage of the phage reproduction cycle, is reported to be effective for the control of bacterial pathogenic bacteria. Bioinformatic analysis of the SPN9CC bacteriophage genome revealed a gene that encodes an endolysin with a domain structure similar to those of the endolysins produced by the P1 and P22 coliphages. The SPN9CC endolysin was purified with a C-terminal oligo-histidine tag. The endolysin was relatively stable and active over a broad temperature range (from 24°C to 65°C). It showed maximal activity at 50°C, and its optimum pH range was from pH 7.5 to 8.5. The SPN9CC endolysin showed antimicrobial activity against only gram-negative bacteria and functioned by cutting the glycosidic bond of peptidoglycan. Interestingly, the SPN9CC endolysin could lyse intact gram-negative bacteria in the absence of EDTA as an outer membrane permeabilizer. The exogenous lytic activity of the SPN9CC endolysin makes it a potential therapeutic agent against gram-negative bacteria.
对耐药细菌的担忧激发了人们对开发控制细菌感染替代方法的兴趣。内溶素是一种噬菌体编码的酶，在噬菌体繁殖周期的末期分解细菌肽聚糖，据报道它对控制细菌病原菌有效。对SPN9CC噬菌体基因组的生物信息学分析揭示了一个编码内溶素的基因，其结构域结构与P1和P22大肠杆菌噬菌体产生的内溶素相似。用C端寡聚组氨酸标签纯化了SPN9CC内溶素。该内溶素在较宽的温度范围（24°C至65°C）内相对稳定且具有活性。它在50°C时显示出最大活性，其最适pH范围为pH 7.5至8.5。SPN9CC内溶素仅对革兰氏阴性菌具有抗菌活性，其作用方式是切断肽聚糖的糖苷键。有趣的是，在没有作为外膜通透剂的EDTA的情况下，SPN9CC内溶素可以裂解完整的革兰氏阴性菌。SPN9CC内溶素的外源性裂解活性使其成为一种潜在的抗革兰氏阴性菌治疗剂。
