title: Purification and characterization of two novel antimicrobial peptides Subpeptin JM4-A and Subpeptin JM4-B produced by Bacillus subtilis JM4.
abstract: 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.
authors.affiliation: Molecular Microbiology Research Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100080, PR China.
authors.forename: Shimei
authors.initials: S
authors.lastname: Wu
authors.forename: Shifang
authors.initials: S
authors.lastname: Jia
authors.forename: Dandan
authors.initials: D
authors.lastname: Sun
authors.forename: Meiling
authors.initials: M
authors.lastname: Chen
authors.forename: Xiuzhu
authors.initials: X
authors.lastname: Chen
authors.forename: Jin
authors.initials: J
authors.lastname: Zhong
authors.forename: Liandong
authors.initials: L
authors.lastname: Huan
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001412:Bacillus subtilis / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D005591:Chemical Fractionation; D002845:Chromatography; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008970:Molecular Weight; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D012988:Soil Microbiology; D013696:Temperature
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; C511799:subpeptin JM4-A, Bacillus subtilis; C511800:subpeptin JM4-B, Bacillus subtilis