scholarly journals Identification and Characterization of pantocin wh-1, a Novel Cyclic Polypeptide Produced by Pantoea dispersa W18

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 485 ◽  
Author(s):  
Tieshan Teng ◽  
Xianghui Li ◽  
Lei Zhang ◽  
Yanzhang Li

Pantoea dispersa W18, isolated from contaminated soil, was found to exert antimicrobial activity against Mycobacterium species, including Mycobacterium tuberculosis, an important human pathogen. Here, the anti-mycobacterial compound produced by Pantoea dispersa W18 was purified by a combination of hydrophobic interaction chromatography, cation exchange chromatography, and reverse phase HPLC. Active compounds from Pantoea dispersa W18 were identified as a natural peptide named pantocin wh-1 with a 1927 Da molecular weight. The primary structure of this compound was detected by N-terminal amino acid sequencing. The amino acid sequence of pantocin wh-1 consisted of 16 amino acid residues with a cyclic structure. The pantocin wh-1 could be inactivated by protease K, but was heat stable and unaffected by pH (2–12). However, the activity was not completely inactivated by trypsin and pepsin. This is the first report of a cyclic polypeptide purified from a strain of Pantoea dispersa.

2009 ◽  
Vol 75 (6) ◽  
pp. 1552-1558 ◽  
Author(s):  
Naruhiko Sawa ◽  
Takeshi Zendo ◽  
Junko Kiyofuji ◽  
Koji Fujita ◽  
Kohei Himeno ◽  
...  

ABSTRACT Lactococcus sp. strain QU 12, which was isolated from cheese, produced a novel cyclic bacteriocin termed lactocyclicin Q. By using cation-exchange chromatography, hydrophobic interaction chromatography, and reverse-phase high-performance liquid chromatography, lactocyclicin Q was purified from culture supernatant, and its molecular mass was determined to be 6,062.8 Da by mass spectrometry. Lactocyclicin Q has been characterized by its unique antimicrobial spectrum, high level of protease resistance, and heat stability compared to other reported bacteriocins of lactic acid bacteria. The amino acid sequence of lactocyclicin Q was determined chemically, and this compound is composed of 61 amino acid residues that have a cyclic structure with linkage between the N and C termini by a peptide bond. It showed no homology to any other antimicrobial peptide, including cyclic bacteriocins. On the basis of the amino acid sequences obtained, the sequence of the gene encoding the prepeptide lactocyclicin Q was obtained. This is the first report of a cyclic bacteriocin purified from a strain belonging to the genus Lactococcus.


1989 ◽  
Vol 261 (3) ◽  
pp. 993-998 ◽  
Author(s):  
H Sobek ◽  
H Görisch

The carboxylesterase (serine esterase, EC 3.1.1.1) from Sulfolobus acidocaldarius was purified 940-fold to homogeneity by an improved purification procedure with a yield of 57%. In the presence of alcohols the enzyme catalyses the transfer of the substrate acyl group to alcohols in parallel to hydrolysis. The results show the existence of an alcohol-binding site and a competitive partitioning of the acyl-enzyme intermediate between water and alcohols. Aniline acts also as a nucleophilic acceptor for the acyl group. On the basis of titration with diethyl p-nitrophenyl phosphate, a number of four active centres is determined for the tetrameric carboxylesterase. The sequence of 20 amino acid residues at the esterase N-terminus and the amino acid composition are reported.


2000 ◽  
Vol 38 (7) ◽  
pp. 2557-2562 ◽  
Author(s):  
Seung-Hyun Lee ◽  
Bum-Joon Kim ◽  
Jong-Hyun Kim ◽  
Kyung-Hee Park ◽  
Seo-Jeong Kim ◽  
...  

We determined the nucleotide sequences (329 bp) of therpoB DNAs from 22 reference strains ofBorrelia. No insertions or deletions were observed. Deduced amino acid sequences of amplified rpoB DNA comprised 109 amino acid residues (N450 to M558[Escherichia coli numbering]). All amino acid sequences were identical with the exception of those of Borrelia lusitaniae PotiB2 (T461→A) and B. bissettii DN127 (I498→V). Each species of B. burgdorferi sensu lato was differentiated as a distinct entity in the phylogenetic tree constructed by a neighbor-joining method. B. burgdorferi sensu lato could be distinguished from B. turicatae and B. hermsii, which are associated with relapsing fever. Seventeen Korean isolates could be identified by PCR-linked direct sequencing and restriction analysis of the rpoB DNA. These results suggest that rpoB DNA is useful for identification and characterization of Borrelia. In addition, we developed the rapid species identification method using the species-specific primer sets based on rpoB gene sequences.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhongying Wang ◽  
Qixuan Wang ◽  
Hao Wu ◽  
Zhiwu Huang

Abstract Background Prestin (SLC26A5) is responsible for acute sensitivity and frequency selectivity in the vertebrate auditory system. Limited knowledge of prestin is from experiments using site-directed mutagenesis or domain-swapping techniques after the amino acid residues were identified by comparing the sequence of prestin to those of its paralogs and orthologs. Frog prestin is the only representative in amphibian lineage and the studies of it were quite rare with only one species identified. Results Here we report a new coding sequence of SLC26A5 for a frog species, Rana catesbeiana (the American bullfrog). In our study, the SLC26A5 gene of Rana has been mapped, sequenced and cloned successively using RNA-Seq. We measured the nonlinear capacitance (NLC) of prestin both in the hair cells of Rana’s inner ear and HEK293T cells transfected with this new coding gene. HEK293T cells expressing Rana prestin showed electrophysiological features similar to that of hair cells from its inner ear. Comparative studies of zebrafish, chick, Rana and an ancient frog species showed that chick and zebrafish prestin lacked NLC. Ancient frog’s prestin was functionally different from Rana. Conclusions We mapped and sequenced the SLC26A5 of the Rana catesbeiana from its inner ear cDNA using RNA-Seq. The Rana SLC26A5 cDNA was 2292 bp long, encoding a polypeptide of 763 amino acid residues, with 40% identity to mammals. This new coding gene could encode a functionally active protein conferring NLC to both frog HCs and the mammalian cell line. While comparing to its orthologs, the amphibian prestin has been evolutionarily changing its function and becomes more advanced than avian and teleost prestin.


2004 ◽  
Vol 186 (15) ◽  
pp. 4885-4893 ◽  
Author(s):  
Takane Katayama ◽  
Akiko Sakuma ◽  
Takatoshi Kimura ◽  
Yutaka Makimura ◽  
Jun Hiratake ◽  
...  

ABSTRACT A genomic library of Bifidobacterium bifidum constructed in Escherichia coli was screened for the ability to hydrolyze the α-(1→2) linkage of 2′-fucosyllactose, and a gene encoding 1,2-α-l-fucosidase (AfcA) was isolated. The afcA gene was found to comprise 1,959 amino acid residues with a predicted molecular mass of 205 kDa and containing a signal peptide and a membrane anchor at the N and C termini, respectively. A domain responsible for fucosidase activity (the Fuc domain; amino acid residues 577 to 1474) was localized by deletion analysis and then purified as a hexahistidine-tagged protein. The recombinant Fuc domain specifically hydrolyzed the terminal α-(1→2)-fucosidic linkages of various oligosaccharides and a sugar chain of a glycoprotein. The stereochemical course of the hydrolysis of 2′-fucosyllactose was determined to be inversion by using 1H nuclear magnetic resonance. The primary structure of the Fuc domain exhibited no similarity to those of any glycoside hydrolases (GHs) but showed high similarity to those of several hypothetical proteins in a database. Thus, it was revealed that the AfcA protein constitutes a novel inverting GH family (GH family 95).


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