Iqbal A, Ali S A, Abbasi A, Volter W, Rasool S A
Department of Microbiology, University of Karachi, Karachi-75270, Pakistan.
J Basic Microbiol. 2001;41(1):25-36. doi: 10.1002/1521-4028(200103)41:1<25::AID-JOBM25>3.0.CO;2-9.
Staphylococcus aureus AB201, a clinical isolate from wound pus, produced a bacteriocin-like inhibitory substance termed as Bac201, that was inhibitory to Streptococcus agalactiae, Enterococcus faecalis, Acinetobacter calcoaceticus, Neisseria meningitidis and a number of staphylococcal species. It was purified to homogeneity by ammonium sulfate precipitation, gel filtration (BioSil-SEC-125), and reversed-phase high performance liquid chromatography (Vydac C4). The native Bac201 was sized at approximately 170-kDa as determined by GF HPLC. Fraction-I (native Bac201), having antibacterial activity was also examined by transmission electron microscopy and appeared as globular structure showing resemblance with phage-like objects. The purification of Bac201 resulted in 466-fold increase in specific activity and recovery of 0.94% of total antibacterial activity. The purified Bac201 migrated as single band on SDS-PAGE with an estimated molecular mass of about 41-kDa. Bac201 was sensitive to proteolytic enzymes, resistant to heat and organic solvents, and active over a wide range of pH (2.5-10). The amino acid composition revealed a general resemblance with other reported high molecular mass bacteriocins and predominance of glycine (39%), proline (13%) and alanine (8%) residues. Further results showed that Bac201 has a bactericidal effect on sensitive cells which is not produced by either cell lysis or apparent loss of membrane permeability.
金黄色葡萄球菌AB201是从伤口脓液中分离出的一株临床菌株，它产生了一种名为Bac201的类细菌素抑制物质，该物质对无乳链球菌、粪肠球菌、醋酸钙不动杆菌、脑膜炎奈瑟菌以及多种葡萄球菌具有抑制作用。通过硫酸铵沉淀、凝胶过滤（BioSil-SEC-125）和反相高效液相色谱（Vydac C4）将其纯化至同质。通过凝胶过滤高效液相色谱法测定，天然Bac201的大小约为170 kDa。还通过透射电子显微镜检查了具有抗菌活性的组分I（天然Bac201），其呈现出球状结构，与噬菌体样物体相似。Bac201的纯化使比活性提高了466倍，总抗菌活性回收率为0.94%。纯化后的Bac201在SDS-PAGE上迁移为单一条带，估计分子量约为41 kDa。Bac201对蛋白水解酶敏感，对热和有机溶剂具有抗性，并且在较宽的pH范围（2.5 - 10）内具有活性。氨基酸组成显示与其他报道的高分子量细菌素总体相似，甘氨酸（39%）、脯氨酸（13%）和丙氨酸（8%）残基占主导。进一步的结果表明，Bac201对敏感细胞具有杀菌作用，这种作用不是由细胞裂解或明显的膜通透性丧失所产生的。
