• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.485-490
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• 1997

Gluten peptide was produced from corn gluten by enzymatic hydrolysis. This peptide had an ability to increased the solubility of calcium owing to protect calcium ions from forming precipitates of calcium phosphate in the presence of phosphate ions. The solubility of calcium was increased 5.2 times in the presence of 8.3 mg peptide produced by the treatment of papain. These peptides contained high acidic amino acids and fractionated by Delta pack column into fractions No. 1, No. 2 and No. 3. Among them the fraction No. 3 had the highest calcium binding capacity.

• Bioinformatics and Biosystems
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• v.1 no.2
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• pp.109-114
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• 2006

In proteomics research, proteins are digested into peptides by an enzyme and in mass spectrometer, these peptides break into fragment ions to generate tandem mass spectra. The tandem mass spectral data obtained from the mass spectrometer consists of the molecular weights of the precursor ion and fragment ions. The precursor ion mass of tandem mass spectrum is the first value that is fetched to sort the candidate peptides in the database search. We look far the peptide sequences whose molecular weight matches with precursor ion mass of the mass spectrum. Then, we choose one peptide sequence that shows the best match with fragment ions information. The precursor ion mass of the tandem mass spectrum is compared with that of the digested peptides of protein database within the mass tolerance that is assigned by users according to the mass spectrometer accuracy. In this study, we used reversed sequence database method to analyze the molecular weight distribution of precursor ions of the tandem mass spectra obtained by the FT LTQ mass spectrometer for human plasma sample. By reinterpreting the precursor ion mass distribution, we could compute the experimental accuracy and we suggested a method to improve the protein identification performance.

• KSBB Journal
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• v.25 no.4
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• pp.395-400
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• 2010

Papain hydrolysate of fibroin was found to be mainly composed of several even-numbered peptides that can be produced at a large scale and can be used as a precursor for biological fine-chemicals such as peptide detergents. Thus, the hydrolysate was further modified to synthesize a peptide mixture of glyceryl esters using the identical enzyme for the production of such chemicals. Formation of glyceryl ester of each peptide was confirmed by identifying peaks of the nominal mass shift of +74 Da in mass spectrometry. Analysis of the mass spectra indicated that glyceryl esters of di- and tetra-peptides were the major constituents of the mixture and that alanylglycine was most preferentially esterified. It also suggests that papain prefers dipeptide to tetrapeptide and alanine to serine or tyrosine at $P_2$ position as substrate for glyceryl esterification. The glyceryl esters were recovered using ion exchange resin and the yield of glyceryl esterification recorded was 17.8% by weight.

• Journal of the Korean Chemical Society
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• v.51 no.4
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• pp.318-323
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• 2007

Electronic photofragmentation spectrum of protonated tyrosine-alanine dipeptide ions(YAH+) was obtained in the wavenumber region of 34500~36700 cm-1 using a quadrupole ion trap time-of-flight mass spectrometer (QIT-TOFMS). YAH+ ions were produced by electrospray ionization, stored in the ion trap and then irradiated by ultraviolet laser pulses which induced photofragmentation of the ions. The electronic photofragmentation spectrum was obtained by monitoring the photodissociation yields of YAH+ ions as a function of the laser wavelength. The spectrum exhibited two broad peaks which were assigned as S1 and S2 by theoretical calculations using a time-dependent density functional method. The broad widths of the peaks in the spectrum were explained by the overlaps of the peaks originated from various conformers of YAH+ ions which were present in the gas phase at room temperature and also by the contributions of the hot bands.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.75-88
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• 2014

본 연구에서는 비선형 Poisson-Boltzmann 식의 해를 구할 수 있는 웹 기반 EPBS를 이용하여 이온채널의 전하 분포와 유전률이 이온채널의 이온선택성에 미치는 영향에 대해 알아본다. 모델로 사용한 이온채널은 이온채널과 유사한 구조를 갖는 합성 단백질인 고리형 펩타이드 나노튜브와 자연계에 존재하는 Gramicidin A 이다. 계산 결과로부터 용매인 물과 단백질의 유전율 차이에 의해 이온이 이온채널을 통과할 때 반응장이 생성되며, 이는 이온과 상호작용을 통해 이온 종류에 관계없이 이온 통과를 방해하는 에너지 장벽을 형성함을 알 수 있다. 한편, 두 이온채널 부분 전하, 특히 골격에 존재하는 카르보닐기의 쌍극자 모멘트에 의해 이온채널 내부에는 0 보다 작은 정전기 퍼텐셜이 형성된다. 이온채널 내부의 총 정전기 퍼텐셜은 이온채널의 부분 전하에 의한 정전기 퍼텐셜과 유전률 차이에 의한 반응장의 합으로 나타나며, 계산 결과 0 보다 작은 값을 갖는다. 이로부터 본 연구에서 사용된 두 종류의 이온채널이 양이온에 선택성이 있음을 알 수 있다.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.145-149
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• 2012

Cecropin is a well-studied antimicrobial peptide that play important role as key factor in insect humoral immunity. In this study, cecropin-like antimicrobial peptide was isolated and purified from the larval haemolymph of immune-challenged japanese oak silkworm, Antheraea yamamai. To isolate antimicrobial peptide, we separated and compared acidic extracted hemolymph protein bends between control and immune-challenged larvae using SDS-PAGE analysis. In the immune hemolymph extract, but not of non-immune hemolymph, we detected differential expressed peptide band with molecular mass 4,223.01 Da. To understand this peptide better, we successfully purified this peptide using cation exchange chromatography and gel permeation chromatography. Its N-terminal amino acid sequence obtained by Edman degradation evidenced a significant degree of identity with other lepidopteran cecropins. The purified A. yamamai cecropin-like peptide showed a broad spectrum of activity against fungi, Gram-negative and Gram-positive bacteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5602-5609
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• 2014

This study examined the remineralization effect of CPP-ACFP according to the etching time and the frequency of application. A CPP-ACFP paste was formed from a combination of CPP-ACP paste and fluorine. The remineralization effect of CPP-ACFP was measured according to the etching time and the frequency of applications of CPP-ACFP. The microhardness of 64 teeth was measured as the sound sample and observed by scanning electron microscopy. As a result, the effect on remineralization of the enamel increased with increasing etching time and frequency of application. Therefore, a CPP-ACP paste combination to fluorine in the tooth mineral CPP-ACFP paste fluoride application can be supplied with the material-advisable enamel remineralization.

• 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.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.28-28
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• 1992

브라디키닌은 체내에서 강력한 혈관 확장 작용을 일으키는 autacoid(local hormone)로서 혈압의 항상성 유지, 모세혈관 투과성 증진, 염증 및 통증 반응 등에 관여하고 여러 장관 평활근을 수축시킨다. 또한 septic 혹은 endotoxic shock의 여러 원인 물질로도 생각되어진다. 최근 rhinovirus로 인한 감기의 제증상 원인 물질로도 브라디키닌이 주목을 받고있다. 이와같이 브라디키닌온 다양한 질병에 있어 중요한 원인 물질로 여겨지므로 브라디키닌 길항제들은 한두 질병의 치료제로 개발될 가능성이 높음이 강력히 제시되고 있는 실정이다. 이의 개발을 위해서 브라디키닌 수용체에 대한 연구는 필수적이라고 할 수 있다. 본 연구는 두 부분으로 나누어 진행중인데 첫째, 이제까지 보고된 브라디키닌 길항 물질들은 대부분이 브라디키닌의 특정 아미노산 잔기를 치환시킨 펩타이드 유도체로서 이들을 경구 투여시 peptidase어 의하여 쉽게 분해되고 또한 부분적인 효능제 활성을 갖는 불리한 점을 감안하여, 비펩타이드성 브라디키닌 길항제를 개발할 목적으로 한방 및 민간에서 자주 사용되어온 생약중에 브라디키닌 작용에 선택적 길항효과가 있는 물질을 검색한 바 활성을 보인 황금으로부터 작용 성분을 추적중에 있다. 둘째, 브라디키닌 수용체를 순수하게 분리 정제하기 위한 첫 단계로서 이 수용체의 결합시험(binding assay) 방법을 확립하고 더불어 여러 조직내(흰쥐의 여러 기관, 토끼 및 사람의 신장)의 브라디키닌 수용체의 분포를 파악하는 일이다. 횐쥐 조직의 실험 결과로부터 신장에 브라디키닌 수용체가 많이 분포함을 확인되었고 향후 토끼 신장으로부터 동수용체를 분리하고자 한다. 또한 토끼 신장의 근위세뇨관일차배양세포을 이용하여 브라디키닌의 신장에서의 작용기전도 살펴보고 있다.+}$, $Na^{+}$, NH$_{4}$$^{+}$ 및 H$^{+}$) 수용액 메디움에서의 Cd(II), Mg(II) 및 Zn(II)의 Dowex 1-X8, Cl$^{-}$ 수지에 대한 흡착은 역시 어떤 메디움에서도 Cd(II) 흡착이 제일 크며, 다음이 Zn(II) 이고 착이온을 형성않는 Mg(II)이 제일 작았다. 한편 메디움 종류별 D값의 크기순위는 H$^{+}$>K$^{+}$> $Na^{+}$>NH$_{4}$$^{+}$이였다. 메디움의 종류에 따라 D값의 차이가 나는 것은 금속이온의 착이온 형성과 금속이온의 용액내에서의 이온종의 상태와 관련이 있다고 생각된다. 마. MCl(M:K$^{+}$, $Na^{+}$, NH$_{4}$$^{+}$ 및 H$^{+}$)과 MNO$_{3}$ 용리액에 의한 Cd(II), Mg(II) 및 Zn(II)의 용리는 예상한 바와 같이 MCl에서 작은 Dv 값을 갖는데, 이것은 CdCl$_{4}$$^{2-}$ 착이온을 형성하거나 ZnCl$_{4}$$^{2-}$ , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어떠한 용리액에서던지 NH$_{4}$$^{+}$의 경우

• Journal of Life Science
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• v.27 no.1
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• pp.50-56
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• 2017

An antibacterial peptide was purified from an acidified gill extract of the pufferfish Takifugu pardalis. The acidified gill extract was put through a Sep-Pak C18 solid phase extraction cartridge using a stepwise gradient and divided into a flow-through (F.T.) and 60% methanol fraction (RM 60). Among the eluents, RM 60 had potent antibacterial activity against Bacillus subtilis KCTC 1021. RM 60 was partially purified on a cationic-exchange column (SP-5PW) by a linear gradient, and the antibacterial peptide was then further purified, using a series of cationic-exchange and $C_{18}$ reversed-phase HPLC columns. For characterization of the purified peptide, its molecular weight and amino acid sequence were analyzed by MALDI-TOF MS and Edman degradation. The molecular weight of the peptide was about 1171.6 Da. The amino acid sequence of the peptide was partially determined as: STKEKAPRKQ. A comparison of the N-terminal amino acid sequence of the purified peptide with that of other known polypeptides revealed high homology with the N-terminus of the histone H3 protein, which belongs to the histone H3 family. Thus, this peptide was designated as a puffer fish gill (PFG)-related antimicrobial peptide. This is the report to describe an antimicrobial function for the N-terminus of histone H3 of an animal species. The findings suggest that this peptide plays a significant role in the innate defense system of the pufferfish.