• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.445-450
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• 1996

Gelatinase A is a member of the matrix metalloproteinases that play an important role in cancer invasion and metastasis. In the course of screening gelatinase A inhibitors from microbial sources, a fungal strain PT-262 showed a strong inhibitory activity. The strain was identified as Chaunopycnis alba on the basis of its morphological characteristics. The inhibitor was isolated from acetone extract of mycelial cake by sequential chromatographies on MCI-gel, Sephadex LH-20, and a reverse-phase HPLC column. The purified inhibitor was identified as pyridoxatin by its physico-chemical properties and spectroscopic analysis. Pyridoxatin is not a peptide analog and has cyclic hydroxamic acid moiety. It inhibited activated gelatinase A with an $IC_{50}$ value of 15.2 ${\mu}M$ using fluorescent synthetic peptide. It also had a strong cytotoxicity against human cancer cell lines in vitro. Furthermore, this compound inhibited DNA synthesis with an $IC_{50}$ value of 2.92 ${\mu}M$ in PC-3 prostate cancer cells by [$^3H$]thymidine incorporation assay.

• Molecules and Cells
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• 제22권3호
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• pp.328-335
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• 2006

Imperatoxin A ($IpTx_a$), a 3.7 kDa peptide from the African scorpion Pandinus imperator, is an agonist of the skeletal muscle ryanodine receptor (RyR1). In order to study the structure of the toxin and its effect on RyR1, $IpTx_a$ cDNA was PCR-amplified using 3 pairs of primers, and the toxin was expressed in E. coli. The toxin was further purified by chromatography, and various point mutants in which basic amino acids were substituted by alanine were prepared by site-directed mutagenesis. Studies of single channel properties by the planar lipid bilayer method showed that the recombinant $IpTx_a$ was identical to the synthetic $IpTx_a$ with respect to high-performance liquid chromatography mobility, amino acid composition and specific effects on RyR1. Mutations of certain basic amino acids ($Lys^{19}$, $Arg^{23}$, and $Arg^{33}$) dramatically reduced the capacity of the peptide to activate RyRs. A subconductance state predominated when $Lys^8$ was substituted with alanine. These results suggest that some basic amino acid residues in $IpTx_a$ are important for activation of RyR1, and that $Lys^8$ plays an important role in regulating the gating mode of RyR1.

• Journal of Periodontal and Implant Science
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• 제42권4호
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• pp.113-118
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• 2012

Purpose: The aim of this study was to investigate the effects of synthetic fibronectin (FN) fragments, including fibrin binding sites from amino-terminal FN fragments containing type I repeats 1 to 5, on osteoblast-like cell activity. Methods: Oligopeptides ranging from 9 to 20 amino acids, designated FF1, FF3, and FF5, were synthesized by a solid-phase peptide synthesizing system, and we investigated the effects of these peptides on cell attachment and extent of mineralization using confocal microscopy, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, and Alizarin red S staining. Results: FF3 and FF5 peptides increased the number of attached human osteoblastic cells, and FF3 administration led to prominent cell spreading. Mineralization was increased in FF3 and FF5 compared to FF1 and the untreated control. Conclusions: Taken together, it can be concluded that the fibrin-binding oligopeptides FF3 and FF5 enhanced cell attachment and mineralization on osteoblast-like cells. These results indicate that FF3 and FF5 have the potential to increase osteoblast-like cell activity. Performing an in vivo study may provide further possibilities for surface modification of biomimetic peptides to enhance osteogenesis, thus improving the regeneration of destroyed alveolar bone.

• Plant Biotechnology Reports
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• 제3권4호
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• pp.317-324
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• 2009

The insecticidal toxin gene of Bacillus thuringiensis (Bt) is one of the most commonly used in the development of genetically modified (GM) crops. In this research, we analyzed Bt rice showing lepidopteran pest-resistance. The Bt gene is a synthetic Cry1Ac composed of optimal codons for plants, and the Bt protein is targeted to the chloroplast by a transit peptide. Three Cry1Ac rice events (C103-3, C127-1, and C7-1) were analyzed for molecular characterization. C103-3 contains two copies of T-DNA where the left border (LB) region is truncated. Both C7-1 and C127-1 have a single copy of T-DNA, but a part of the vector backbone DNA is inserted into the genome of C127-1; thus, only C7-1 had intact T-DNA. Progenies of C7-1 crossed with the original cultivar, Nakdong, and double-haploid lines from anther culture of lines crossed with the elite cultivar, Dongjin, were analyzed for T-DNA flanking genomic DNA and genotyping. Results showed that an intact T-DNA region without the vector backbone was inserted into the genome and was stably inherited through generations. The C7-1 homozygous event could be used as breeding material to develop GM rice with pest resistance.

• 한국축산식품학회지
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• 제34권3호
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• pp.339-345
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• 2014

This study was performed to develop a rapid immuno-assay kit, by using a specific antigen to detect Hanwoo brand meat. We selected a synthetic antigen specific to our target antibody, named BIO-TAG (Tyr-D-Ala-Phe), by utilizing a computer-based analysis and literature review. BIO-TAG tagged with adjuvant was subcutaneously injected in sheep and Hanwoo. The serum and meat juice of the immunized or non-immunized animal were then analyzed, to measure the titer of antibody by ELISA and Western blot. The amount of antibodies against the BIO-TAG increased (p<0.05) in serum by vaccination. Furthermore, meat juice from the immunized Hanwoo showed greater (p<0.05) antibody titer, compared with those from non-immunized groups. To optimze the dilution factor, we performed dot-ELISA, with various combination levels of BIO-TAG. Results from dot-ELISA showed that 2 mg/mL BIO-TAG was sufficient to distinguish the immunized meat from non-immunized groups. These results support our hypothesis that simple immunization of Hanwoo generates a sufficient amount of antibodies to be detectable in the meat juice by means of the immune-assay. Therefore, specific Hanwoo brand meat can be more precisely identified by our rapid diagnostic kit. This technology can deter possible fraud of counterfeit meat brands in the Korean domestic market with ease and rapidity; and offers a new tool that guarantees consumers high quality Hanwoo brand beef.

• Journal of Periodontal and Implant Science
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• 제40권5호
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• pp.211-219
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• 2010

Purpose: Fibronectin (FN) has been shown to stimulate bone regeneration in animal models. The aim of this study was to evaluate the capacity of bovine bone mineral coated with synthetic oligopeptides to enhance bone regeneration in rabbit calvarial defects. Methods: Oligopeptides including fibrin-binding sequences of FN repeats were synthesized on the basis of primary and tertiary human plasma FN structures. Peptide coated and uncoated bone minerals were implanted into 10 mm calvarial defects in New Zealand white rabbits, and the animals were sacrificed at 4 or 8 weeks after surgery. After specimens were prepared, histologic examination and histomorphometric analysis were performed. Results: At 4 weeks after surgery, the uncoated groups showed a limited amount of osteoid formation at the periphery of the defect and the oligopeptide coated groups showed more osteoid formation and new bone formation in the center of the defect as well as at the periphery. At 8 weeks, both sites showed increased new bone formation. However, the difference between the two sites had reduced. Conclusions: Fibrin-binding synthetic oligopeptide derived from FN on deproteinized bovine bone enhanced new bone formation in rabbit calvarial defects at the early healing stage. This result suggests that these oligopeptides can be beneficial in reconstructing oral and maxillofacial deformities or in regenerating osseous bone defects.

• Restorative Dentistry and Endodontics
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• 제45권3호
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• pp.31.1-31.20
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• 2020

Matrix metalloproteinases (MMPs) are enzymes that can degrade collagen in hybrid layer and reduce the longevity of adhesive restorations. As scientific understanding of the MMPs has advanced, useful strategies focusing on preventing these enzymes' actions by MMP inhibitors have quickly developed in many medical fields. However, in restorative dentistry, it is still not well established. This paper is an overview of the strategies to inhibit MMPs that can achieve a long-lasting material-tooth adhesion. Literature search was performed comprehensively using the electronic databases: PubMed, ScienceDirect and Scopus including articles from May 2007 to December 2019 and the main search terms were "matrix metalloproteinases", "collagen", and "dentin" and "hybrid layer". MMPs typical structure consists of several distinct domains. MMP inhibitors can be divided into 2 main groups: synthetic (synthetic-peptides, non-peptide molecules and compounds, tetracyclines, metallic ions, and others) and natural bioactive inhibitors mainly flavonoids. Selective inhibitors of MMPs promise to be the future for specific targeting of preventing dentin proteolysis. The knowledge about MMPs functionality should be considered to synthesize drugs capable to efficiently and selectively block MMPs chemical routes targeting their inactivation in order to overcome the current limitations of the therapeutic use of MMPs inhibitors, i.e., easy clinical application and long-lasting effect.

• 생명과학회지
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• 제22권3호
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• pp.387-397
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• 2012

군소인 Aplysia kurodai의 중추신경절로부터 정제된 myomodulin A (MMA)가 정제되었다. MMA의 일차구조는 Pro-Met-Ser-Met-Leu-Arg-Leu-$NH_2$이며, 이 펩타이드는 다른 연체동물에서 발견된 myomodulin 계열의 펩타이드와 같은 구조를 지닌다. 정제된 MMA는 Mytilus edulis의 anterior byssus retractor muscle (ABRM)에서 phasic contraction을 조절하는 것으로 나타났다. MMA의 구조와 활성간의 상관관계를 알아보기 위해서 MMA, Des[$Pro^1$]-MMA, Des[$Pro^1,Met^2$]-MMA, Des[$Pro^1,Met^2,Ser^3$]-MMA 및 MME를 합성하였다. Des[$Pro^1$]-MMA, Des[$Pro^1,Met^2$]-MMA 및 Des[$Pro^1,Met^2,Ser^3$]-MMA의 일차구조는 각각 Met-Ser-Met-Leu-Arg-Leu-$NH_2$, Ser-Met-Leu-Arg-Leu-$NH_2$ 및 Met-Leu-Arg-Leu-$NH_2$이다. MMA 및 합성 물질들을 사용하여 ABRM 및 Achatinafulica의 소낭과 penial retractor muscle에 대해 활성을 측정하였다. MMA는 $1{\times}10^{-8}$ M 또는 더 낮은 농도에서 ABRM의 수축활성을 증가시키는 것으로 나타났지만, $1{\times}10^{-8}$ M 또는 고농도에서는 phasic contraction을 억제하였다. MMA와 유도체들은 소낭에 대해서는 수축반응을 보였지만, penial retractor muscle에 대해서는 이완 활성을 나타내었다. 이러한 결과들은 MMA의 C-말단부위에 있는 Met-Leu-Arg-Leu-$NH_2$가 ABRM의 수축반응뿐만 아니라 연체동물의 생식기능 및 소화 활성을 조절하기 필요한 최소한의 구조라는 것을 나타낸다.

• Journal of Periodontal and Implant Science
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• 제33권4호
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• pp.543-553
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• 2003

Due to considerably high degree of sequence homology between bacterial and human heat shock proteins(hsp), it has been widely thought that this protein might be involved in autoimmune disease mechanisms in humans. To elucidate how stress proteins contribute in the immunopathogenesis of periodontitis, the present study was performed to evaluate the T cell immune responses specific to Porphyromonas gingivalis (P. gingivalis) heat shock protein (hsp)60 and T-cell epitope specificities for P. gingivalis hsp60 in periodontitis. Anti-P. gingivalis IgG antibody titers were elevated in all patients. We could establish P. gingivalis hsp-specific T cell ines from the peripheral blood of peridontitis, a mixture of $CD4^+$ and $CD8^+$ cells. Of 108 overlapping synthetic peptides spanning whole P. gingivalis hsp60 moleculc, ten peptides with cpitopes specifities for T-cell were showed. Interestingly, ten epitopes were also identified as T-cell epitopes in the present study as well as B-cell epitopes in peridontitis. Therefore, all the ten representative epitopes were designated as common T-and B-cell epitopes for peridontitis. It is critical in developing a peptide vaccine strategy for potential prevention of periodontitis. It was concluded that P. gingivalis hsp60 might be involved in the immunoregulatory process of periodontitis with heat shock protein specificities.

• 한국균학회지
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• 제14권2호
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• pp.101-107
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• 1986

The properties of carboxyl proteinase which was contained in Poria cocos (Schw.) Wolf were investigated by means of the purification with 0.65 ammonium sulfate saturation, DEAE cellulose and Sephadex G-75 gel filtration. This enzyme was found to hydrolyze only peptide bond between glutamyl-L-tyrosine of carbobenzoxy-L-glutamyl-L-tyrosine among the synthetic substrates of carbobenzoxy-L-glutamyl-L-tyrosine, hippuryl- L-phenylalanine and hippuryl-L-arginine. This enzyme was inhibited by $Zn^{+2},\;Fe^{+2},\;Ca^{+2},\;CN^{-1},\;P_2O_7^{-4}$ ions, but stimulated by $Hg^{+2}$ ion. Also, this enzyme was inhibited by organic compounds such as L-lysine, L-phenylalanine, hippuryl-L-phenylalanine, diazoacetyl-DL-norleucine methyl ester (DAN) and 1,2-epoxy-3-(P-nitrophenoxy)propane(EPNP). In particular, the activity was inhibited by L-lysine till 20 minutes of preincubation time rapidly, and by DAN in the presence of $Cu^{+2}$ ion more rapidly after 30 minutes than DAN in the absence of $Cu^{+2}$ ion. L-Lysine was found to be a competitive inhibitor and its $K_i$ value was determined to be 0.12 mmole by Dixon plot.