• Title/Summary/Keyword: 펩타이드-효소 상호작용

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Neuropeptides in Clinical Psychiatric Research : Endorphins and Cholecystokinins (정신질환에 있어서의 신경펩타이드 연구 - Endorphin과 cholecystokinin을 중심으로 -)

  • Kim, Young Hoon;Shim, Joo Chul
    • Korean Journal of Biological Psychiatry
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    • v.5 no.1
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    • pp.34-45
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    • 1998
  • We provide the reader with a brief introduction to the neurobiology of neuropeptides. Several comprehensive reviews of the distribution and neurochemical, neurophysiological, neuropharmacological and behavioral effects of the major neuropeptides have recently appeared. In reviews of the large number of neuropeptides in brain and their occurance in brain regions thought to be involved in the pathogenesis of major psychiatric disorders, investigators have sought to determine whether alternations in neuropeptide systems are associated with schizophrenia, mood disorders, anxiety disorders, alcoholism and neurodegenerative disease. There is no longer any doubt that neuropeptide-containing neurons are altered in several neuropsychiatric disorders. One of the factors that has hindered neuropeptide research to a considerable extent is the lack of pharmacological agents that specifically alter the synaptic availability of neuropeptides. With the exception of naloxone and naltrexone, the opiate-receptor antagonists, there are few available neuropeptide- receptor antagonists. Two independent classes of neuropeptide-receptor antagonists has been expected to be clinically useful. Naltrexone, a potent ${\mu}$-receptor antagonist, has been used successfully to reduce the need for alcohol consumption. And cholecycstokinin antagonists are now in development as a new class of anxiolytics, which would be expected to be free from tolerance and physical dependence and lack of sedation. In this review, we deal with these two kinds of neuropeptide system, the opioid system and cholesystokinins in the brain. The role of opioid systems in the reinforcement after alcohol consumtion and that of cholesystokinins in the pathogenesis of anxiety will be discussed briefly. As we know, the future for neuropeptides in psychiatry remains bright indeed.

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Stimulation of Nitric Oxide Production in RAW 264.7 Macrophages by the Peptides Derived from Silk Fibroin. (실크 피브로인 유래 펩타이드에 의한 RAW 264.7 Macrophage의 Nitric Oxide 생성 촉진)

  • 박금주;현창기
    • Microbiology and Biotechnology Letters
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    • v.30 no.1
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    • pp.39-45
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    • 2002
  • It was found that the peptides originated from the hydrolysates of silk fibroin have in vitro immunostimulating effects in murine macrophage RAW264.7 cells. The stimulation effects on nitric oxide (NO) production resulted from treatments of acid or enzymatic hydrolysates were measured. The silk fibroin preparation isolated from cocoon was most efficiently digested by acid hydrolysis. Even though the sole treatment of acid hydrolysate stimulated the NO production in dose-dependent pattern, a part of its activity was found to be caused by the contaminated endotoxin, LPS. When each endotoxin-free hydrolysates obtained by filtering it through an ultrafiltration membrane of molecular weight (MW) cut-off 10,000 to eliminate LPS was used, the peptic hydrolysate with lowest degree of hydrolysis showed the highest activity. The fractions of peptic hydrolysate with MW ranges of 1,000∼10,000, 500∼1,000 and below 500 also showed a higher MW-higher activity correlation. From the analyses of amino acid composition of each hydrolysate, it was found that the contents of arginine, lysine, alanine and glycine residues affected the activity level of hydrolysate. The results of this study showed a possibility of utilizing fibroin as a source for immunostimulating (chemopreventive) functional peptides.

Functional Role of Peptide Segment Containing 1-25 Amino Acids in N-terminal End Region of ErmSF (ErmSF에서 특이적으로 발견되는 N-terminal end region에 존재하는 1-25번째 아미노산을 함유하는 peptide segment의 효소 활성에서의 역할)

  • Jin, Hyung-Jong
    • Korean Journal of Microbiology
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    • v.42 no.3
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    • pp.165-171
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    • 2006
  • ERM proteins transfer the methyl group to $A_{2058}$ in 23S rRNA to confer the resistance to MLS (macrolide-lincosamide-streptogramin B) antibiotics on microorganism ranging from antibiotic producers to pathogens. To define the functional role of peptide segment encompassing amino acid residues 1 to 25 in NTER (N-terminal end region) of ErmSF, one of the ERM proteins, DNA fragment encoding mutant protein deprived of that peptide was cloned and overexpressed in E. coli to obtain a purified soluble form protein to the apparent homogeneity in the yield of 12.65 mg per liter of culture. The in vitro activity of mutant protein was found to be 85% compared to wild type ErmSF, suggesting that this peptide interact with substrate to affect the enzyme activity. This diminished activity of mutant protein caused the delayed expression of antibiotic resistance in vivo, that at fIrst cells expressing mutant protein showed the retarded growth due to the antibiotic action but with time cells inhibited by antibiotic gradually recovered the viability to exert the resistance to the same extent as those with wild type protein.

A Study of Salty Enhanceability of Enzymatically Hydrolyzed Isolated Soy Protein (분리 대두 단백 효소가수분해물의 강도평가를 통한 짠맛증진효과 연구)

  • Kim, Jin Seon;Shin, Jung-Kue
    • Food Engineering Progress
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    • v.21 no.2
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    • pp.138-142
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    • 2017
  • This study investigated the possible use of enzymatically hydrolyzed isolated soy protein (eHISP) to enhance the intensity of salty taste. The sodium chloride content of eHISP is 69.5 g/L. Yellowness (b) increased, and lightness (L) and redness (a) decreased with increasing eHISP concentration in sample solution. Also, perceived salty intensity of eHISP solution increased in sample solution with increasing added amount of eHISP with same NaCl concentration. The intensity of the salty taste was enhanced by 2-39% as the eHISP was added. The results suggest that it may be possible to reduce the content of sodium chloride in foods by enhancing the salty taste with eHISP.

Anti-inflammatory Activity of Antimicrobial Peptide Protaetiamycine 2 Derived from the Protaetia brevitarsis seulensis (흰점박이꽃무지 유래 항균 펩타이드 프로테티아마이신 2의 항염증활성)

  • Lee, Joon Ha;Baek, Minhee;Lee, Hwa Jeong;Kim, In-Woo;Kim, Sun Young;Seo, Minchul;Kim, Mi-Ae;Kim, Seong Hyun;Hwang, Jae Sam
    • Journal of Life Science
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    • v.29 no.11
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    • pp.1218-1226
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    • 2019
  • The white-spotted flower chafer Protaetia brevitarsis seulensis is a medicinally beneficial and important edible insect species. We previously performed an in silico analysis of the Protaetia brevitarsis seulensis transcriptome to identify putative antimicrobial peptides and then tested their antimicrobial and hemolytic activities. These peptides had potent antimicrobial activities against bacteria and yeast without inducing hemolysis. In the present study, the cationic antimicrobial peptide, protaetiamycine 2, was selected for further assessment of its anti-inflammatory properties in mouse macrophage Raw264.7 cells. Protaetiamycine 2 treatment of Raw264.7 cells suppressed LPS-induced nitric oxide production and reduced the expression of inducible nitric oxide synthase and cyclooxygenase-2, as determined by real-time PCR and western blotting. The expression of proinflammatory cytokines ($TNF-{\alpha}$, IL-6, and $IL-1{\beta}$) was also attenuated through the MAPKs and $NF-{\kappa}B$ signaling. We also confirmed that protaetiamycine 2 bound to bacterial cell membranes by a specific interaction with LPS. Collectively, these data obtained from LPS-induced Raw264.7 cells indicated that protaetiamycine 2 could have both antimicrobial and anti-inflammatory properties.

Enhancement of Immune Activities of Peptides from Asterias amurensis Using a Nano-encapsulation Process (나노 입자 불가사리 펩타이드의 면역 활성 증진)

  • Jeong, Hyang-Suk;Oh, Sung-Ho;Kim, Seoung-Seop;Jeong, Myoung-Hoon;Choi, Woon-Yong;Seo, Yong-Chang;Choi, Geun-Pyo;Kim, Jin-Chul;Lee, Hyeon-Yong
    • Korean Journal of Food Science and Technology
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    • v.42 no.4
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    • pp.424-430
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    • 2010
  • Immuno-modulatory activities of peptides from Asterias amurensis were investigated using a nano-encapsulation process. The molecular weights of the peptides in the range of 5-7 kDa were separated using Sephadex G-75 gel filtration. Eighty-five percent of the nano-particles were in the 300 nm range using dynamic light scattering. The cytotoxicity of the A. amurensis nano-particles against CCD-986sk human dermal fibroblast cells was 11.64% after adding 1.0 mg/mL of the samples, which was lower than that from the control (13.28% collagen). The secretion of $NO^-$ from macrophages was estimated as $40\;{\mu}M$ after adding 1.0 mg/mL of gelatin nano-particles, which was higher than the others. Prostaglandin $E_2$ production from UV-induced human skin cells decreased greatly to 860 pg/mL after adding 1.0 mg/mL of the samples. Confocal microscopy revealed that nano-particles effectively penetrated the cells within 1 hour. From these results, we consider that nano-encapsulation of the peptides from A. amurensis can improve their biological functions.

Anti-inflammatory Activity of Antimicrobial Peptide Zophobacin 1 Derived from the Zophobas atratus (아메리카왕거저리 유래 항균 펩타이드 조포바신 1의 항염증활성)

  • Shin, Yong Pyo;Lee, Joon Ha;Kim, In-Woo;Seo, Minchul;Kim, Mi-Ae;Lee, Hwa Jeong;Baek, Minhee;Kim, Seong Hyun;Hwang, Jae Sam
    • Journal of Life Science
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    • v.30 no.9
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    • pp.804-812
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    • 2020
  • The giant mealworm beetle, Zophobas atratus (Coleoptera: Tenebrionidae) has been used as a protein source for small pets and mammals. Recently, it was temporarily registered in the list of the Food Code. We previously performed an in silico analysis of the Zophobas atratus transcriptome to identify putative antimicrobial peptides and identified several antimicrobial peptide candidates. Among them, we assessed the antimicrobial and anti-inflammatory activities of zophobacin 1 that was selected bio-informatically based on its physicochemical properties against microorganisms and mouse macrophage Raw264.7 cells. Zophobacin 1 showed antimicrobial activities against microorganisms without inducing hemolysis and decreased the nitric oxide production of the lipopolysaccharide-induced Raw264.7 cells. Moreover, ELISA and Western blot analysis revealed that zophobacin 1 reduced expression levels of pro-inflammatory enzymes such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). We also investigated expression of pro-inflammatory cytokines (interleukin-6 and interleukin-1β) production through quantitative real time-PCR and ELISA. Zophobacin 1 markedly reduced the expression level of cytokines through the regulation of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB) signaling. We confirmed that zophobacin 1 bound to bacterial cell membranes via a specific interaction with lipopolysaccharides. These data suggest that zophobacin 1 could be promising molecules for development as antimicrobial and anti-inflammatory therapeutic agents.