• Journal of Plant Biotechnology
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• v.46 no.4
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• pp.282-290
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• 2019

Cuphea viscosissima plants accumulate medium-chain fatty acids (MCFAs), i.e., those containing 8 ~ 14 carbons, in their seeds, in addition to the longer carbon chain fatty acids (≥16 carbons) found in a variety of plant species. Previous studies have reported the existence of three C. viscosissima MCFA-producing acyl-acyl carrier protein (ACP) thioesterases with different substrate specificities. In this study, CvFatB4, a novel cDNA clone encoding an acyl-ACP thioesterase (EC 3.1.2.14), was isolated from developing C. viscosissima seeds. Sequence alignment of the deduced amino acid sequence revealed that four catalytic residues for thioesterase activity are conserved and a putative N-terminal chloroplast transit peptide is present. Overexpression of CvFatB4 cDNA, which was under the control of the cauliflower mosaic virus 35S promoter, in Arabidopsis thaliana led to an increase in 16:0 fatty acid (palmitate) levels in the seed oil at the expense of 18:1 and other non-MCFAs.

• Journal of Periodontal and Implant Science
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• v.35 no.1
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• pp.1-8
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• 2005

Bacterial heat shock protein has been one of the components that are responsible to induce autoimmune disease mechanisms in the pathogenesis of atherosclerosis due to high level of homology in sequence with human counterpart. This mechanism may explain how bacterial infectious disease, such as periodontal disease, might contribute to the acceleration of the disease process of atherosclerosis. Porphyromonas gingivalis which is a major periodontal pathogenic bacterial species, has been implicated as one of the pathogenic bacteria playing the role in this context. The present study has been performed to evaluate the anti-atherosclerotic effect of adoptive transfer of Porphyromonas gingivalis heat shock protein epitope-specific T cell lines into severe combined immunodeficiency (SCID) mice. Peptide no. 15 with amino acid sequence VKEVASKTND-specific T cell line was selected for the transfer. When experimental atherosclerosis was induced in SCID mice adoptively transferred either by the T cell lines (experimental group) or by non-specific mouse T cells (control group), there was no significant difference in the severity and extent of the atherosclerosis induced by hypercholesterol diet.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.38-42
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• 2002

A chitinase gene (pCHi58) encoding a 58 kDa chitinase was isolated from the Serratia marcescens KCTC 2172 cosmid library. The chitinase gene consisted of a 1686 bp open reading frame that encoded 562 amino acids. Escherichia coil harboring the pChi58 gene secreted a 58 kDa chitinase into the culture supernatant. The 58 kDa chitinase was purified using a chitin affinity column and mono-S column. A nucleotide and N-terminal amino acid sequence analysis showed that the 58 kDa chitinase had a leader peptide consisting of 23 amino acids which was cleaved prior to the 24th alanine. The 58 KDa chitinase exhibited a $98\%$ similarity to that of S. marcescens OMB 1466 in its nuclotide sequence. The chitinolytic patterns of the 58 kDa chitinase released N,N'-diacetyl chitobiose (NAG2) as the major hydrolysis end-product with a trace amount of N-acetylglucosamine. When a 4-methylumbellyferyl-N-acetylglucosamin monomer, dimmer, and tetramer were used as substrates, the 58 kDa chitinase did not digest the 4-Mu-NAG monomer $(analogue\;of\;NAG_2)$, thereby indicating that the 58 kDa chitinase was likely an endochitinase. The optimum reaction temperature and pH of the enzyme were $50^{\circ}C$ and 5.0, respectively.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.330.2-330.2
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• 2002

The conformational study on cyclic Ac-Cys-Pro-Xaa-Cys-NHMe (Ac-CPXC-NHMe: X = Ala, Val. Leu. Aib. Gly. His. Phe, Tyr. Asn. and Ser) peptides has been carried out using the ECEPP/3 force field and the hydration shell model in the unhydrated and hydrated states. This work has been undertaken to investigate structural implications of the CPXC sequence as the chain reversal for the initiation of protein folding and as the motif for active site of disulfide oxidoreductases. The backbone conformation DAAA is in common the most feasible for cyclic CPXC peptides in the hydrated state. which has a type 1${\beta}$-turn at the Pro-Xaa sequence. The proline residue and the hydrogen bond between backbones of two cystines appear to play a role in stabilizing this preferred conformation of cycilc CPXC peptides. However. the distributions of backbone conformations and ${\beta}$-turns may indicate that the cyclic CPXC peptide seems to exist as an ensemble of ${\beta}$-turns and coiled conformations. The intirnsic stability of the cyclic CPXC motif itself the active conformation appears to play a role in determining electrochemical properties of disulfide oxidoreductases.

• Journal of Animal Science and Technology
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• v.66 no.1
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• pp.232-236
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• 2024

Ligilactobacillus is a genus of Gram-positive lactobacilli commonly found in the intestinal tracts of vertebrates. It has been granted a Qualified Presumption of Safety (QPS) status from the European Food Safety Authority (EFSA). One specific strain, Ligilactobacillus salivarius B4311, was isolated from fecal samples of broiler chickens from a farm associated with Chung-Ang University (Anseong, Korea). This strain was observed to have inhibitory effects against Listeria monocytogenes. In this paper, we present the complete genome sequence of Lig. salivarius B4311. The whole genome of strain B4311 comprises 2,071,255 bp assembled into 3 contigs representing a chromosome, repA-type megaplasmid, and small plasmid. The genome contains 1,963 protein-coding sequences, 22 rRNA genes, and 78 tRNA genes, with a guanine + cytosine (GC) content of 33.1%. The megaplasmid of strain B4311 was found to contain the bacteriocin gene cluster for salivaricin P, a two-peptide bacteriocin belonging to class IIb.

• BMB Reports
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• v.38 no.1
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• pp.58-64
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• 2005

Myo-inositol monophosphate phosphatase (IMPP) is a key enzyme in the phosphoinositide cell-signaling system. This study found that incubating the IMPP from a porcine brain with pyridoxal-5'-phosphate (PLP) resulted in a time-dependent enzymatic inactivation. Spectral evidence showed that the inactivation proceeds via the formation of a Schiff's base with the amino groups of the enzyme. After the sodium borohydride reduction of the inactivated enzyme, it was observed that 1.8 mol phosphopyridoxyl residues per mole of the enzyme dimer were incorporated. The substrate, myo-inositol-1-phosphate, protected the enzyme against inactivation by PLP. After tryptic digestion of the enzyme modified with PLP, a radioactive peptide absorbing at 210 nm was isolated by reverse-phase HPLC. Amino acid sequencing of the peptide identified a portion of the PLP-binding site as being the region containing the sequence L-Q-V-S-Q-Q-E-D-I-T-X, where X indicates that phenylthiohydantoin amino acid could not be assigned. However, the result of amino acid composition of the peptide indicated that the missing residue could be designated as a phosphopyridoxyl lysine. This suggests that the catalytic function of IMPP is modulated by the binding of PLP to a specific lysyl residue at or near its substrate-binding site of the protein.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.278-284
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• 2007

A novel screening strategy for salt-resistant antimicrobial peptides from a M13 peptide library was developed. Fusion of MSI-344, a magainin derivative and indolicidin to pIII coat proteins did not significantly affect viability of the recombinant phages, which indicated that the pIII could neutralize toxicity of the antimicrobial peptides and therefore it is possible to construct antimicrobial peptide library in Escherichia coli. On the basis of the conserved sequence of ${\alpha}$-helical antimicrobial peptides, a semi-combinatorial peptide library was constructed in which the peptides were displayed by pIII. To remove hemolytic activity from the library, the phages bound to red blood cells were removed, and the subtracted phage library was screened for binding to target bacteria Pseudomonas aeruginosa and Staphylococcus aureus under high salt concentrations. The screened peptides showed relatively low antimicrobial activity against the target bacteria. However, antimicrobial activities of the screened peptides P06 and S18 were not affected by the cation concentrations of 150 mM $Na^+$, 2 mM $Mg^{2+}$ and 2 mM $Ca^{2+}$ without significant hemolytic activity. This screening strategy that is based on binding capacity to target cells provides new potential to develop salt-tolerant antimicrobial peptides.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.127-131
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• 2006

A study was carried out to produce antimicrobial peptides from zein treated with pretenses of six kinds. Among the pretenses of six kinds, zein hydrolysate treated with pepsin showed the highest antimicrobial activity. The zein hydrolysate with pepsin was fractionated with membrane filter (30,000 10,000 and 3,000 molecular weight cut-off) and antimicrobial activity was measured for each fractions. Antimicrobial activity appeared greatly in the fraction below 3,000 (molecular weight cut-off) . The fraction was re-fractionated by HPLC and substances of two peaks collected as a sample to measure antimicrobial activity. All of both peaks showed the antimicrobial activity but 1st peak exhibited a consistently higher antimicrobial activity than 2nd peak. Minimum inhibitory concentrations (MIC) were between 2.5 and 3.0 mg/mL. The peptide was heat-stable since antimicrobial activity was maintained after treated with heat for 20 min at $121^{\circ}C$. N-terminal amino acid sequence of peptide fractionated by HPLC was leucine, glutamic acid, proline, phenylalanine, aspartic acid and argenine. These results indicated that peptide isolated from zein hydrosate with pepsin can use as a natural preservative ingredient in food industry.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.1
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• pp.30-34
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• 2003

A hagfish bradykinin(BK)-related peptide was isolated and characterized from the skin of hagfish, Eptatretus burgeri. The hagfish BK with a molecular mass of 875.8 Da was purified to a homogeneity using $C_{18}$ reverse-phase and cation-exchange high performance liquid chromatography. The primary structure of the hagfish BK was determined as Gly-Thr-Ala-Gly-Ile-Gly-Pro-Phe-Arg by a combination of an automated amino acid sequencing and MALDI-TOF mass spectrometry. This amino acid sequence contains five substitutions $(Arg^1{\rightarrow}Gly,\;Pro^2{\rightarrow}Thr,\;Pro^3{\rightarrow}Ala,\;Phe^5{\rightarrow}Ile,\;Ser^6{\rightarrow}Gly)$ compared with that of mammalian BK. The hagfish BK showed a contractile action on the intestine of hagfish, Eptatretus burgeri. The threshold concentration of hagfish BK was around $10^{-11}\;M.$

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1555-1563
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• 2008

A novel $\alpha$-amylase ($\alpha$-1,4-$\alpha$-D-glucan glucanohydrolase, E.C. 3.2.1.1), ScAmy43, was found in the culture medium of the phytopathogenic fungus Sclerotinia sclerotiorum grown on oats flour. Purified to homogeneity, ScAmy43 appeared as a 43 kDa monomeric enzyme, as estimated by SDS-PAGE and Superdex 75 gel filtration. The MALDI peptide mass fingerprint of ScAmy43 tryptic digest as well as internal sequence analyses indicate that the enzyme has an original primary structure when compared with other fungal a-amylases. However, the sequence of the 12 N-terminal residues is homologous with those of Aspergillus awamori and Aspergillus kawachii amylases, suggesting that the new enzyme belongs to the same GH13 glycosyl hydrolase family. Assayed with soluble starch as substrate, this enzyme displayed optimal activity at pH 4 and $55^{\circ}C$ with an apparent $K_m$ value of 1.66 mg/ml and $V_{max}$ of 0.1${\mu}mol$glucose $min^{-1}$ $ml^{-1}$. ScAmy43 activity was strongly inhibited by $Cu^{2+}$, $Mn^{2+}$, and $Ba^{2+}$, moderately by $Fe^{2+}$, and was only weakly affected by $Ca^{2+}$ addition. However, since EDTA and EGTA did not inhibit ScAmy43 activity, this enzyme is probably not a metalloprotein. DTT and $\beta$-mercaptoethanol strongly increased the enzyme activity. Starting with soluble starch as substrate, the end products were mainly maltotriose, suggesting for this enzyme an endo action.