• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.355-362
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• 2016

The phosphomannomutase/phosphoglucomutase gene (pmm/pgm) of Vibrio anguillarum (the causative agent of fish vibriosis) was cloned, and the open reading frame corresponded to a protein with 446 amino acids. The pmm/pgm gene showed a significant degree of sequence homology with the previously reported genes from V. mimicus, V. vulnificus, V. splendidus, and V. harveyi, with 92.3%, 91.4%, 89.9%, and 89.9% amino acid identity, respectively. By reverse transcriptase-polymerase chain reaction, we found that the pmm/pgm gene was upregulated under cold stress condition. The PMM/PGM protein is known to catalyze the interconversion between mannose-1-phosphate and mannose-6-phosphate or glucose-1-phosphate and glucose-6-phosphate, which are important intermediates for lipopolysaccharide (LPS) biosynthesis. To confirm the role of PMM/PGM in the LPS biosynthetic pathway, we constructed a knock out mutant by homologous recombination. The respective LPSs were isolated from the V. anguillarum wild-type and mutant strains, and changes were compared by subjecting them to sodium dodecyl sulfate polyacrylamide gel electrophoresis. Based on the different patterns of the LPSs, we expect the pmm/pgm gene to have an important role in LPS biosynthesis. The pmm/pgm-deficient mutant of V. anguillarum will contribute to further studies about the role of LPS in V. anguillarum pathogenesis.

• Journal of Life Science
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• v.27 no.11
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• pp.1276-1289
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• 2017

This study isolated and purified the antimicrobial peptide McSSP-31 from an acidified hemocyte extract of a Mytilus coruscus. The antimicrobial peptide was purified by using a $C_{18}$ reversed-phase high-performance liquid chromatography (HPLC). The peptide was determined to be 3330.549 Da by matrix assisted-laser desorption ionization time-of-flight mass spectrophotometer (MALDI-TOF/MS). The N-terminus of a 14 amino-acid sequence was identified as P-S-P-T-R-R-S-T-S-R-S-K-S-R by Edman degradation method. The acquired sequence showed a 93% similarity with the sperm-specific protein Phi-1, which is from M. californianus. The identified open-reading frame (ORF) of peptide was 306 bp encoding 101 amino acids, which was analyzed by rapid amplification of cDNA ends (RACE), cloning and sequencing analysis. We compared the full sequence with other known proteins that reveal the sperm-specific protein Phi-1 (93.5%) of M. californianus. Synthesized antimicrobial peptide (McSSP-31) showed antibacterial activity against gram-positive bacteria including B. subtilis, S. mutans, S. aureus and gram-negative bacteria including E. coli, K. pneumoniae, P. mirabilis, P. aeruginosa and fungi, C. albicans. Also, synthesized peptide showed strong antibacterial activity against antibiotic-resistant strains, including S. aureus. The cytotoxicity of the peptide was determined by using the HUVEC human cell line. The peptide did not exhibit any significant cytotoxic effects on the normal human cell line, and it had very low hemolytic activity with flounder hemoglobin. The results demonstrated that peptide purified from the hemocyte of a M. coruscus exhibits antibacterial activity against various bacteria and has the potential to be an alternative antibiotic agent.

• Korean Journal of Food Science and Technology
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• v.6 no.3
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• pp.177-184
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• 1974

File fish Navodon modestus was dehydrated in cabinet type hot-sir drier at $48-50^{\circ}C$ for 11 hours and also yellowfin puffer Fugu xanthopterum was dried in open air at $26-28^{\circ}C$ for 30 hours. Nucleotides and their related compounds were collected by extraction with cold perchloric acid and their amounts were determined by anion exchange column chromatography. The contents of ADP, IMP, ATP and hypoxanthine in fresh file fish muscle were 22.9, 12.1, 4.9, and 3.2 ${\mu}mole/g,$ dry wt. respectively. AMP and inosine were 0.9 ${\mu}mole/g,$ dry wt. equally. In fresh yellowfin puffer muscle, the contents of ADP, ATP, AMP, inosine and hypoxanthine were 25.6, 2.4, 1.6, 0.3, 0.6, and 0.4 ${\mu}mole/g,$ dry wt. respectively. In the case of file fish, ADP and ATP tended to degrade rapidly during hot-air dehydration. The contents of IMP were decreased slightly while AMP and inosine were increased. And another case of yellowfin puffer, ADP also tended to degrade rapidly during sun drying while AMP, IMP, inosine and hypoxanthine were increased. Especially, in both case of file fish and yellowfin puffer, inosine was increased twenty five and thirty five times during drying respectively.

• Journal of Life Science
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• v.27 no.7
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• pp.796-804
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• 2017

This study was carried out to evaluate the antioxidant effect of methanolic extract of Houttuynia cordata (HCME) and to identify a compound having antioxidant effect. The ethyl acetate fraction of HCME showed the highest antioxidant effect in organic solvent fractions. The fraction was then separated into 12 fractions by open column chromatography. Among these fractions, the fraction 10 (Fr. 10) with the highest antioxidant activity was isolated, and its antioxidant effect was evaluated by DPPH radical scavenging activity, reducing power, TBARS, cell viability, DNA oxidation and DCF fluorescence. The Fr. 10 at a $64{\mu}g/ml$ showed 60% of inhibitory effect similar to that of vitamin C at $10{\mu}g/ml$, compared with blank group. The Fr. 10 at $64{\mu}g/ml$ showed 264% of reducing power, compared with blank group. TBARS assay showed that the Fr. 10 at $64{\mu}g/ml$ had 35.5% of inhibitory effect similar to that of vitamin E at $1,000{\mu}g/ml$, compared with blank group. The Fr. 10 above $32{\mu}g/ml$ displayed cytotoxicity. However, it was observed that the Fr. 10, above $1{\mu}g/ml$ reduced DNA damage. DCF fluorescence assay showed that the Fr. 10 inhibited oxidative stress by $H_2O_2$ in a dose dependent manner. The compound of Fr. 10 was identified to be rutin whose molecular weight is 610 by the IR and LC-MS analyses. Therefore, these results suggest that the rutin of Fr. 10 could use as a natural antioxidant for development of cosmetics and functional foods.

• Food Science and Preservation
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• v.24 no.1
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• pp.93-99
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• 2017

Collagen synthesis is decreased and matrix metalloproteinase-1 (MMP-1) levels are increased in naturally aged human skin, and these alterations cause changes such as skin wrinkling and decreased elasticity. As a part of our ongoing search for bioactive ingredients, MMP-1 inhibitory and type-1 procollagen synthesis inducing activities of aqueous methanolic extract of manufactured gambir product from Uncaria gambir were investigated in in vitro bioassay systems. In addition, total phenolic contents were quantified using a spectrophotometric method. Among tested samples, 40% MeOH eluate from 80% methanolic extract of manufactured U. gambir using open column chromatography packed with Diaion HP-20 resin showed significant MMP-1 inhibitory activities with an $IC_{50}$ value of $15.6{\pm}1.3{\mu}g/mL$. Furthermore, type-1 procollagen synthesis promoting property of 40% MeOH eluate ($IC_{50}$ value; $6.9{\pm}0.7{\mu}g/mL$) from 80% methanolic extract of manufactured gambir was higher than other eluates. Additionally, the present investigation revealed that 40% MeOH eluate of manufactured gambir product contained a high level of total phenolic compounds. The result suggests a distinct relationship between anti-wrinkle activity and total phenolic contents, and manufactured gambir product could be considered a new effective source of natural bioactive ingredients. Systematic investigation of manufactured gambir product will be performed for further development of its biological properties.