Crupper S S, Gies A J, Iandolo J J
Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City 73190, USA.
Appl Environ Microbiol. 1997 Nov;63(11):4185-90. doi: 10.1128/aem.63.11.4185-4190.1997.
The bacteriocin BacR1 was purified from culture supernatant of Staphylococcus aureus UT0007 by sequential ammonium sulfate precipitation, cation-exchange chromatography, and C4 reverse-phase chromatography steps. Mass spectrographic analysis indicated that the purified peptide has a molecular mass of 3,338 Da. It is resistant to environmental conditions, retaining full biological activity after exposure to pH extremes (pHs 3 to 11), heating at 95 degrees C for 15 min, and exposure to strong chaotropic agents. BacR1 was destroyed with a complete loss of biological activity after digestion with trypsin and proteinase K. Amino acid sequence analysis revealed a high concentration of Asx, Gly, and Pro residues and a high proportion of hydrophobic amino acids. The peptide is bactericidal and kills in a dose-dependent manner, but it does not lyse log-phase cells of Corynebacterium renale, the routine indicator organism for bacteriocin assay. A specific receptor for binding was detected on sensitive cells but not on insensitive cells. Competition assays showed that UV-inactivated cells could protect susceptible cells from antibacterial action. A partial inhibitory spectrum revealed that organisms from the following genera are susceptible: Staphylococcus, Streptococcus, Corynebacterium, Haemophilus, Bordetella, Moraxella, Pasteurella, Neisseria, and Bacillus.
通过连续的硫酸铵沉淀、阳离子交换色谱和C4反相色谱步骤，从金黄色葡萄球菌UT0007的培养上清液中纯化出细菌素BacR1。质谱分析表明，纯化后的肽分子量为3338 Da。它对环境条件具有抗性，在暴露于极端pH值（pH 3至11）、95℃加热15分钟以及暴露于强变性剂后仍保留全部生物活性。用胰蛋白酶和蛋白酶K消化后，BacR1被破坏，生物活性完全丧失。氨基酸序列分析显示，Asx、Gly和Pro残基的浓度较高，疏水氨基酸比例较高。该肽具有杀菌作用，且杀菌作用呈剂量依赖性，但它不会裂解肾棒状杆菌的对数期细胞，肾棒状杆菌是细菌素检测的常规指示菌。在敏感细胞上检测到了特异性结合受体，而在不敏感细胞上未检测到。竞争试验表明，紫外线灭活的细胞可以保护敏感细胞免受抗菌作用。部分抑制谱显示，以下属的微生物敏感：葡萄球菌属、链球菌属、棒状杆菌属、嗜血杆菌属、博德特氏菌属、莫拉克斯氏菌属、巴斯德氏菌属、奈瑟氏菌属和芽孢杆菌属。
