Wu Shimei, Jia Shifang, Sun Dandan, Chen Meiling, Chen Xiuzhu, Zhong Jin, Huan Liandong
Molecular Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100080, PR China.
Curr Microbiol. 2005 Nov;51(5):292-6. doi: 10.1007/s00284-005-0004-3. Epub 2005 Oct 5.
An antimicrobial peptides-producing strain was isolated from soil and identified as Bacillus subtilis JM4 according to biochemical tests and 16S rDNA sequence analysis. The corresponding antimicrobial peptides were purified to homogeneity by ammonium sulfate precipitation, sequential SP-Sepharose Fast Flow, Sephadex G-25 and C18 reverse-phase chromatography, and in the final purification step, two active fractions were harvested, designated as Subpeptin JM4-A and Subpeptin JM4-B. The molecular weights, determined by mass spectrometry, were 1422.71 Da for Subpeptin JM4-A and 1422.65 Da for Subpeptin JM4-B, respectively. Amino acid sequencing showed that they differed from each other only at the seventh amino acid except for three unidentified residues, and the two peptides had no significant sequence homology to the known peptides in the database, indicating that they are two novel antimicrobial peptides. In addition, characteristic measurements indicated that both peptides had a relatively broad inhibitory spectrum and remained active over a wide pH and temperature range.
从土壤中分离出一株产抗菌肽的菌株，经生化试验和16S rDNA序列分析鉴定为枯草芽孢杆菌JM4。通过硫酸铵沉淀、连续的SP-Sepharose Fast Flow、Sephadex G-25和C18反相色谱法将相应的抗菌肽纯化至同质，在最终纯化步骤中，收获了两个活性组分，分别命名为Subpeptin JM4-A和Subpeptin JM4-B。通过质谱测定，Subpeptin JM4-A的分子量为1422.71 Da，Subpeptin JM4-B的分子量为1422.65 Da。氨基酸测序表明，除了三个未鉴定的残基外，它们仅在第七个氨基酸处彼此不同，并且这两种肽与数据库中的已知肽没有明显的序列同源性，表明它们是两种新型抗菌肽。此外，特性测定表明这两种肽均具有相对较宽的抑制谱，并且在较宽的pH和温度范围内保持活性。
