• Journal of the Korean Chemical Society
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• v.46 no.1
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• pp.46-51
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• 2002

The recognition and cleavage of 5S rRNA from P. alcaligenes by metallopeptides to the form $Ni(II){\cdot}Gly$-Gly-His(Arg)COOH and $Cu(II){\cdot}Gly$-Gly-His(Arg)COOH were investigated. The results of RNA cleavage analyses suggest that metallopeptides selectively target the unpaired or unstably paired bases of stem-loop structure of 5S rRNA. The selectivity of metallopeptides was little affected by the species of metal ion, Ni(II) or Cu(II). When the result of cleavage by metallopeptides was compared with that of by metal complexes M(II)CR, the recognition by metallopeptides was more selective and structure specific. The cleavage data by metallopeptides and other metal complexes were used to probe the secondary structure of 5S rRNA from P. alcaligenes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1273-1278
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• 2007

In living system, various types of metal chelated protein show their intrinsic biological activities. In order to investigate the chelation reaction between protein and metal, zinc chelated peptide was systhesized by the peptide, hydrolyzed protein, with zinc. And simple analytical method fot the chelation reaction was developed using MALDI-TOF mass spectrometry.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.2
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• pp.157-167
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• 2022

In this study, we investigated the effects of heptapeptide on cellular activation and inhibition of cellular damage induced by photoaging condition in NIH3T3 fibroblasts. Cell proliferation and extracellular matrix (ECM) expression were induced by heptapeptide. The reduced cell viability under photoaging condition through ultraviolet A (UVA) irradiation was increased by heptapeptide. And UVA-induced apoptosis, matrix metalloproteinases-1 (MMP-1) expression, and reactive oxygen species (ROS) level were decreased by heptapeptide. In addition, the inhibition of transforming growth factor-β (TGF-β)/smad signaling under UVA irradiation which resulting in reduction of ECM expression was also recovered by heptapeptide. We also tested the effect of heptapeptide under another photoaging condition through heat shock, and pre-treatment of heptapeptide prevented the phosphorylation of mitogen-activated protein kinase (MAPK) and MMP-1 expression induced by heat shock. From these results, it has been shown that the heptapeptide has protective effects on fibroblasts through the up-regulation of cellular activity and through the decreasing of intracellular ROS level induced by UVA irradiation or heat shock. It is expected that the dermal protection effect of heptapeptide can be applied as a new cosmetic material in the future.

• Journal of Periodontal and Implant Science
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• v.33 no.1
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• pp.27-35
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• 2003

1. 목적 생체재료의 생체친화성을 증진시키고 치유를 촉진하기 위한 목적으로 생체재료의 생화학적 표면개질에 관한 연구가 널리 진행되고 있다. 이와 같은 목적으로 이용되어 온 부착분자에는 아미노산, 펩타이드, 단백질, 효소 및 성장인자들을 들 수 있으며, 이들 분자들을 금속, 골대체물질 및 폴리머와 같은 생체재료의 표면개질에 이용하여 왔다. 이 연구의 목적은 생체적합성이 우수하고 생분해성을 지닌 키토산으로 얇은 막을 제작한 후, 세포외 기질의 구성성분 중 세포부착에 관여하는 RGD 펩타이드를 부착시킨, 표면개질 키토산막의 생물학적 영향을 MG-63 조골양세포를 이용하여 관찰하는 것이다. 2. 방법 2% acetic acid에 키토산 가루를 녹여 만든 2% 키토산 용액으로 24-well 배양접시의 표면을 도포 후 24시간 동안 건조시켜 키토산막을 제작하였다. GRGDS 펩타이드를 cross-linker(EDC, NHS) (Sigma, MO, USA) 용액과 반응시켜서 펩타이드의 카르복실기를 활성화시켰다. 이들을 PBS 완충용액으로 수화시킨 키토산막과 결합시켜 펩타이드의 활성화된 카르복실기와 키토산의 아민기 간에 안정적인 아미드 결합(amide bond)이 형성되도록 하였다. 하루 동안 반응을 일으킨 후 PBS 완충용액과 증류수로 씻어내고 냉동 건조시킴으로써 GRGDS가 결합된 키토산막을 제작하였다. 재료 표면의 화학 성분을 알아보는데 사용되는 방법의 일종인 X-ray photoelectron spectroscopy(XPS) 분석을 통하여 부착분자가 키토산막에 결합된 여부를 확인하였다. GRGDS 펩타이드에 요오드를 결합시킨 후, 이것을 키토산막에 공유 결합시키고 XPS를 통해 요오드가 재료 표면에서 검출되는지를 검사하였다. 요오드가 검출된다면 이것은 키토산막 표면에 실제로 GRGDS 펩타이드가 존재하는 것을 의미하게 된다. 표면개질된 키토산막에 사람조골양세포인 MG-63을 접종하여 이를 실험군으로 하였고, 표면이 개질 되지 않은 키토산막을 대조군으로 하였다. 세포부착의 최적화 농도를 확인하기 위하여 GRGDS를 0.01, 0.05, 0.1, 0.25, 0.5, 1.0mg/ml의 농도로 준비하였다. 배양 후 1일, 7일째에 각 well에서 trypsin EDTA를 이용하여 세포를 분리한 후, 이를 원심 분리하여 세포수측정기를 이용하여 부착 세포의 수를 측정하여 세포의 부착 정도를 비교하였다. 배양 2시간, 24시간 후 주사전자현미경을 이용하여 키토산막에 부착된 세포의 양상을 관찰하였다. 3. 결과 XPS를 통한 표면의 화학 성분 분석 결과 GRGDS 펩타이드를 결합시킨 키토산막에서 요오드가 검출되었으며 펩타이드를 부착하지 않은 대조군에서는 검출되지 않았다. 따라서 cross-linker를 이용한 펩타이드와 키토산막의 공유결합을 확인할 수 있었다. 세포 배양 후 1일째 부착된 세포 수를 측정한 결과 0.1mg/ml 이상의 GRGDS 펩타이드 농도로 공유 결합시킨 키토산막에서 부착 세포 수가 다른 농도에 비해 유의성 있게 많이 관찰되었다. 이 농도 이하에서는 대조군과 실험군간에 세포부착의 유의한 차이가 없었다. 따라서 주사전자현미경을 이용한 부착 세포의 양상에 관한 관찰은 0.1mg/ml 농도의 펩타이드를 이용하였다. 세포 배양 7일째, 부착된 세포 수 측정 결과 GRGDS의 농도에 따른 유의성 있는 차이가 없었으며, 실험군과 대조군간에도 유의성 있는 차이가 없었다. 주사전자현미경 관찰결과 2시간 및 24시간 배양된 실험군 모두에서 별모양의 세포들이 키토산막 표면에 편평하게 잘 부착되어 있으며 많은 위족이 발달된 소견을 보인 반면, 대조군에서는 원형 또는 다각형 모양의 세포들이 실험군에 비해 부착이 덜 되어있는 양상을 보였다. 이 연구를 통하여 기능성 펩타이드를 생체재료의 표면에 공유결합 시키는 방법을 확립할 수 있었으며, RGD 펩타이드의 공유결합으로 표면개질된 키토산막이 조골세포의 부착능을 증진시킬 수 있음을 확인하였다. 표면개질된 생체재료를 소, 중동물에 적용시켜 생체 내에서의 생물학적 영향을 평가할 필요가 있으며, 이 실험의 결과는 향후 다양한 기능성 부착분자를 선발, 고안하여 임플란트용 생체재료의 표면개질에 이용하는 이른바 모방생체재료분야에 널리 활용될 수 있을 것으로 생각된다.

• Korean Journal of Optics and Photonics
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• v.28 no.1
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• pp.9-15
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• 2017

We precisely measured and analyzed the dynamics of peptide-antibody interactions, using an ellipsometric biosensor based on a silicon substrate. To reduce the signal error due to the imperfect flatness of the substrate for extremely low concentrations of peptide, we fabricated the biosensor with a silicon substrate coated with Dextran SAM, instead of a glass prism coated with a thin metallic thin film. At an injection speed of $100{\mu}l/min$ of buffer liquid, we detected the dynamics of antibody-Dextran SAM or peptide-antibody fixed on biosensor, respectively. We detected the dynamics of antibody-Dextran SAM interactions down to a low concentration of 5 ng per liter, and we precisely measured the dynamics of association and dissociation of peptide and antibody down to 100 nM of peptide. We obtained the rate constants for association and dissociation from fitting the data by using deduced dynamical equation. As a result, we obtained an equilibrium constant for dissociation of 97 nM of peptide-antibody complex, which belongs to Class I.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.15-19
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• 2021

In this study, we studied a facile method for the synthesis of stable and nearly spherical gold nanoparticles using a tyrosine-rich peptide, Tyr-Tyr-Gly-Tyr-Tyr (YYGYY), as both the reducing and capping agent. The peptide coated spherical and polycrystalline gold nanoparticles with diameters from 3 to 15 nm were successfully synthesized by varying the concentration of the peptide and metal precursor under UV irradiation. The nanoparticles were then characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). Furthermore, the catalytic activity of gold nanoparticles was confirmed by the reduction of 4-nitrophenol to 4-aminophenol, in which the catalytic reaction rate constant was 7.3 × 10-3 s-1.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.631-642
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• 2017

Protein hydrolysates derived from plants and animals having antioxidant, suppression of hypertension, immunodulatory, alleviation of pain, and antimicrobial activity has been known as playing important role like hormone. This study was performed to hydrolysis of Ogae egg white protein using the six proteases. The antioxidant activity of the produced peptides was analyzed. As a result, the maximum value of hydrolysis was protamex(46.3%), DPPH radical scavenging was bromelain(57.23%), hydroxy radical scavenging was alcalase(30.21%), superoxide radical scavenging was alcalase(58.07%), and $Fe^{2+}$ chelation ability was alcalase(72.06%). Furthermore, the antioxidant Inhibition concentration ($IC_{50}$) of peptides was evaluated for each enzyme. As a result, the maximum value of alcalase was $Fe^{2+}$ cheating ability($IC_{50}$, 1.24 mg/mL), bromelain was DPPH radical scavenging($IC_{50}$, 2.46 mg/mL), flavourzyme was $Fe^{2+}$ cheating ability($IC_{50}$, 1.25 mg/mL), neutrase was DPPH radical scavenging($IC_{50}$, 3.64 mg/mL), papain was DPPH radical scavenging ($IC_{50}$, 3.82 mg/mL) and protamex was DPPH radical scavenging($IC_{50}$, 1.93 mg/mL). Therefore, we expect that peptides produced from Ogae egg white protein using protease enzyme are useful as an antioxidant functional food ingredients.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.338-348
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• 2017

Protein hydrolysates derived from plants and animals having antioxidant, suppression of hypertension, immunodulatory, alleviation of pain, and antimicrobial activity has been known as playing important role like hormone. This study was performed to optimize the hydrolysis of protein of sea of cucumber by a flavourzyme. The ranges of processes were the reaction temperature of 40 to $60^{\circ}C$, pH 6 to 8, and enzyme concentration 0.5 to 1.5%(w/v). As a result, the optimization of process was determined at temperature of $48-50^{\circ}C$, pH of 7.0-7.2, and enzyme concentration of 1.0-1.1%(w/v), and degree of hydrolysis was 43-45 at above conditions. The molecular weight of hydrolysate was distributed to 500-3,500 Da and showed typical peptides. Inhibition concentration ($IC_{50}$) of peptides of DPPH radical scavenging activity, Superoxide anion radical scavenging activity, Hydroxy radical scavenging activity, $Fe^{2+}$ cheating activity was 1.25, 3.40, 10.3, and 22.11 mg/mL, respectively. Therefore, we expect that those products are useful as functional food ingredients.

• Journal of Chest Surgery
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• v.40 no.4 s.273
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• pp.264-272
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• 2007

Background: Vascular endothelial growth factor (VEGF) plays an important role in angiogenesis, including stimulating the proliferation and migration of vascular smooth muscle cells (VSMCs). It has been known that diabetes is associated with accelerated cellular proliferation via VEGF, as compared to that under a normal glucose concentration. We investigated the effects of selective blockade of a VEGF receptor by using anti-Flt-1 peptide on the formation and hyperplasia of the neointima in balloon injured-carotid arteries of OLETF rats and also on the in vitro VSMCS' migration under high glucose conditions. Material and Method: The balloon-injury method was employed to induce neointima formation by VEGF. For f4 days beginning 2 days before the ballon injury, placebo or vascular endothelial growth factor receptor-1 (VEGFR-1) specific peptide (anti-Flt-1 peptide), was injected at a dose of 0.5mg/kg daily into the OLETF rats. At 14 days after balloon injury, the neointimal proliferation and vascular luminal stenosis were measured, and cellular proliferation was assessed by counting the proliferative cell nuclear antigen (PCNA) stained cells. To analyze the effect of VEGF and anti-Flt-1 peptide on the migration of VSMCs under a high glucose condition, transwell assay with a matrigel filter was performed. And finally, to determine the underlying mechanism of the effect of anti-Flt-1 peptide on the VEGF-induced VSMC migration in vitro, the expression of matrix metalloproteinase (MMP) was observed by performing reverse transcription-polymerase chain reaction (RT-PCR). Result: Both the neointimal area and luminal stenosis associated with neointimal proliferation were significantly decreased in the anti-Flt-1 peptide injected rats, ($0.15{\pm}0.04 mm^2$ and $ 36.03{\pm}3.78%$ compared to $0.24{\pm}0.03mm^2\;and\;61.85{\pm}5.11%$, respectively, in the placebo-injected rats (p<0.01, respectively). The ratio of PCNA(+) cells to the entire neointimal cells was also significantly decreased from $52.82{\pm}4.20%\;to\;38.11{\pm}6.89%$, by the injected anti-Flt-1 peptide (p<0.05). On the VSMC migration assay, anti-Flt-1 peptide significantly reduced the VEGF-induced VMSC migration by about 40% (p<0.01). Consistent with the effect of anti-Flt-1 peptide on VSMC migration, it also obviously attenuated the induction of the MMP-3 and MMP-9 mRNA expressions via VEGF in the VSMCS. Conclusion: Anti-Flt-1 peptide inhibits the formation and hyperplasia of the neointima in a balloon-injured carotid artery model of OLETF rats. Anti-Flt-1 peptide also inhibits the VSMCs' migration and the expressions of MMP-3 and MMP-9 mRNA induced by VEGF under a high glucose condition. Therefore, these results suggest that specific blockade of VEGFR-1 by anti-Flt-1 peptide may have therapeutic potential against the arterial stenosis of diabetes mellitus patients or that occurring under a high glucose condition.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.1018-1027
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• 2019

Natural-derived protein-derived low molecular weight peptides have been known to have physiological activities such as antioxidant, hypertension relief, immunomodulation, pain relief and antimicrobial activity. In this study, the low-molecular peptides were produced using commercial proteases (alcalase, bromelain, flavourzyme, neutrase, papain, protamex), and the antioxidant activity (DPPH scavenging activity, superoxide radical scavenging activity, hydroxy radical scavenging activity, and metals chelation capacity), constituent amino acid and molecular weight of the peptide were analyzed. Enzyme reaction was performed by adding 50 g of chopped Ogae meat slurry and 2%(w/v) protein enzyme into the enzyme reactor for 2 h at a pH of 6 and a temperature of $60^{\circ}C$. The degree of hydrolysis(%) after the reaction ranged from $36.65{\pm}4.10%$ to $70.75{\pm}5.29%$. The highest degree of hydrolysis of protamex was 46.3%, and the highest value of papain hydrolysate was $70.75{\pm}5.29%$. On the other hand, alcalase hydrolysate showed the lowest value of $36.65{\pm}4.10%$. Bromelain-treated low molecular weight peptides showed the highest DPPH radical scavenging activity and the lowest scavenging activity of alcalase-treated peptides. Superoxide radical scavenging activity showed that bromelain treated low molecular peptide showed the highest radical scavenging activity of 50% or more. Hydroxyl radical scavenging activity ranged from about 16.73 to 69.16%, the highest among bromelain-treated low molecular peptides. $Fe^{2+}$ chelation abilities showed a distribution between about 17.85 to 47.84%. The chelation capacity of the hydrolysates was not significantly different without any difference to the enzymes used. The results of amino acid analysis showed differences between hydrolysates of alcalase, bromelain, flavourzyme, neutrase, papain, and protamex enzymes. The most amino acid was glutamic acid. The molecular weight distribution of the enzyme hydrolyzates was in the range of 300-2,000 Da, although the molecular weight distribution differed according to the treated enzymes.