• 공업화학
• /
• 제31권1호
• /
• pp.67-72
• /
• 2020

Biomaterials are frequently functionalized with Arg-Gly-Asp (RGD) peptides to provide cell adhesion sites. In this study, RGD peptides were enzymatically coupled on to the surface of fibroin microspheres. Papain exhibited a strong preference for dansyl phenylalanine for the peptide formation with fibroin microspheres. Thus, RGD1 peptide was designed to carry cysteine to both sides of the sequence, glycine as a spacer and two residues of phenylalanine at the C-terminal (CRGDCGFF). The enzymatic modification facilitated by an increasing amount of substrate and by the presence of organic solvent, dimethylsulfoxide at 25% (v/v). Microspheres coupled with RGD1, showed a significantly different precipitation property and an increased apparent volume, possibly due to the steric hindrance of RGD peptides on the surface. Transmission electron microscopy also confirmed the presence of cysteine residues in RGD1 coupled on the surface of microspheres stained with gold nanoparticles. RGD1-microspheres significantly facilitated the growth of murine fibroblast 3T3 cells even under non-adhesion culture conditions.

• 한국식품영양과학회지
• /
• 제3권1호
• /
• pp.69-76
• /
• 1974

The method of amino acid sequence determination from the C-terminal amino acid is proposed and mass spectrometric identification of thiohydantoins described previously. In this paper was discussed the fragmentation of thiohydantoin-ring by deutero substitution and model tripeptide have been degraded through three stages each, with interpretable results. The conditions employed in this method are mild enough for biological materials. The main features of the method are the following. 1. Thiohydantoins were formed in a non-aqueous medium a mixture of acetic anhydride, acetic acid and ammonium thiocyanate. 2. Mass sepectra of thiohydantoins derived from 20 amino acids were obtained with a mass spectrometer, JEOL model JMS-06H. 3. Cleavage of peptidyl thiohydantoin was made with an acidic from of a cation-exchange resin. (Amberlite IR-120) 4. Separation of the cleaved thiohydantoin and the parent peptide less one amino acid moiety was made by chromatography on a Sephadex G-10 column. 5. The peptide fraction was concentrated by freezedrying. 6. Thiohydantoin derivative of carboxyl terminal amino acid residue was introduced with a direct inlet probe in methanol solution.

• Bulletin of the Korean Chemical Society
• /
• 제35권12호
• /
• pp.3627-3631
• /
• 2014

In this study we examined two ester-containing cross-links, hex-2-enyl acetate and hex-2-enyl propionate, as new cross-linking systems for helix stabilization of short peptides. We demonstrated that these hexenyl ester cross-links can be readily installed via a ruthenium-mediated ring-closing metathesis reaction of L-aspartic acid 4-allyl ester or L-glutamic acid 5-allyl ester at position i and (S)-2-(4'-pentenyl)alanine at position i+4 using second generation Hoveyda-Grubbs catalyst at $60^{\circ}C$. Between these two cross-links, we found that the hex-2-enyl propionate significantly stabilizes the ${\alpha}$-helical conformations of short model peptides. The helix-stabilizing effects of the hex-2-enyl propionate tether appear to be as powerful as Verdine's i,i+4 all-hydrocarbon stapling system, which is one of the most widely used and the most potent helix-stabilizing cross-linking systems. Furthermore, the hex-2-enyl propionate bridge is reasonably robust against non-enzymatic hydrolytic cleavage at a physiological pH. While extended studies for probing its chemical scopes and biological applications are needed, we believe that this new helix-stabilizing system could serve as a useful chemical tool for understanding protein folding and designing conformationally-constrained peptide drugs.

• 동의신경정신과학회지
• /
• 제20권2호
• /
• pp.31-46
• /
• 2009

Objectives : This experiment was designed to investigate the effect of Gojineumja(Guzhenyinzi, GJEJ) on damaged neural tissue in cultured glial cells and in the mouse brain tissue. Methods : The effects of the GJEJ on activation of astrocytes and caspase 3-positive cell counts in cultured glial cells administered with ${\beta}$-amyloid peptide were investigated. The effects of the GJEJ on levels of glial fibrillary acidic protein(GFAP)-positive reactive astrocyets and caspase 3-positive cells in the hippocampal subfields in the rats administered with scopolamine were investigated. Results : 1. GJEJ reduced levels of activated astrocytes and caspase 3-positive cell counts in cultured glial cells administered with ${\beta}$-amyloid peptide. 2. GJEJ reduced levels of GFAP-positive reactive astrocyets and caspase 3-positive cells in the hippocampal subfields in the rats administered with scopolamine. Conclusions : The present data. suggest that GJEJ may have a protective function of neuronal and non-neuronal cells in damaged neural tissue caused by AD-like stimulations. Further studies on identification of effective molecular components of GJEJ and their interactions with damaged neural cells would be important for understanding molecular mechanism and may be further applicable for the development of therapeutic strategies.

• Bulletin of the Korean Chemical Society
• /
• 제29권3호
• /
• pp.656-662
• /
• 2008

Antagonists of the d -opioid receptor are effective in overcoming resistance against analgesic drugs such as morphine. To identify novel antagonists of the d -opioid receptor that display high potency and low resistance, we performed 3D-QSAR analysis using chemical feature-based pharmacophore models. Chemical features for d -opioid receptor antagonists were generated using quantitative (Catalyst/HypoGen) and qualitative (Catalyst/HipHop) approaches. For HypoGen analysis, we collected 16 peptide and 16 non-peptide antagonists as the training set. The best-fit pharmacophore hypotheses of the two antagonist models comprised identical features, including a hydrophobic aromatic (HAR), a hydrophobic (HY), and a positive ionizable (PI) function. The training set of the HipHop model was constructed with three launched opioid drugs. The best hypothesis from HipHop included four features: an HAR, an HY, a hydrogen bond donor (HBD), and a PI function. Based on these results, we confirm that HY, HAR and PI features are essential for effective antagonism of the d -opioid receptor, and determine the appropriate pharmacophore to design such antagonists.

• BMB Reports
• /
• 제56권11호
• /
• pp.606-611
• /
• 2023

The main protease (Mpro) of SARS-CoV-2 cleaves 11 sites of viral polypeptide chains and generates essential non-structural proteins for viral replication. Mpro is an important drug target against COVID-19. In this study, we developed a real-time fluorometric turn-on assay system to evaluate Mpro proteolytic activity for a substrate peptide between NSP4 and NSP5. It produced reproducible and reliable results suitable for HTS inhibitor assays. Thus far, most inhibitors against Mpro target the active site for substrate binding. Mpro exists as a dimer, which is essential for its activity. We investigated the potential of the Mpro dimer interface to act as a drug target. The dimer interface is formed of domain II and domain III of each protomer, in which N-terminal ten amino acids of the domain I are bound in the middle as a sandwich. The N-terminal part provides approximately 39% of the dimer interface between two protomers. In the real-time fluorometric turn-on assay system, peptides of the N-terminal ten amino acids, N10, can inhibit the Mpro activity. The dimer interface could be a prospective drug target against Mpro. The N-terminal sequence can help develop a potential inhibitor.

• 한국양식학회지
• /
• 제11권3호
• /
• pp.327-335
• /
• 1998

본 연구는 PCR을 이용하여 brook trout의 성장호르몬 cDNA를 증폭시켰다. 증폭된 brook trout의 성장호르몬 cDNA의 전 염기서열은 1,120bp로 13bp의 5'uncoding region과 477bp의 3'uncoding region 그리고 630bp로 coding되는 210 아미노산 잔기가 open reading frame(ORF)을 구성하고 있음을 알았다, 또한, ORF의 아미노산 배열로부터 22개의 아미노산으로 이루어진 signal peptide 그리고 4개의 cysteine 잔기로부터 2개의 disulfide bond 결합을 하고있었으며, 이는 성장호르몬 단백질이 종을 초월하여 2개의 disulfide bond 결합으로 이루어진 고치구조를 형성하고 있는 것이 시사되었다. 그리고 Atlantic salmon과 97.1%, chum salmon과 94.8%, rainbow trout와 94.3%, coho salmon과 91.9%, tuna와 66.2%, tilapia와 63.5%, yellow tail과 62.9%, carp와 62.3%, flounder와 53.8%, eel과 48.1%의 아미노산 상동성을 나타냈다.

• 미생물학회지
• /
• 제55권3호
• /
• pp.303-305
• /
• 2019

섬 해안가 토양에서 방선균주 Gordonia sp. MMS17-SY073를 분리하여 유전체 분석을 실시하였고, 그 결과 5,962,176 염기쌍 및 67.4%의 G + C 함량으로 이루어진 유전체 정보를 확보하였다. 유전정보 분석 결과 총 5,201개 단백질 지정 유전자, 6개 rRNA 유전자 및 45개 tRNA 유전자를 확인하였다. MMS17-SY073 균주는 16S rRNA 유전자를 이용한 분석 결과 분류학적으로 Gordonia soli의 표준균주와 가장 가까웠으며 그 유사도는 98.5%로 나타났다. MMS17-SY073 균주는 non-ribosomal peptide synthetase 유형을 비롯한 다수의 이차대사산물 생합성 유전자를 보유하고 있는 것으로 나타났다.

• Tuberculosis and Respiratory Diseases
• /
• 제69권4호
• /
• pp.271-278
• /
• 2010

Background: Recent studies have demonstrated that the epidermal growth factor receptor (EGFR) genotype is the most important predictive marker to EGFR-tyrosine kinase inhibitors (TKIs) and first-line gefitinib treatment will be approved in the near future for use in non-small cell lung cancer (NSCLC) patients with the EGFR mutation. Direct sequencing is known to be the standard for detecting EGFR mutations; however, it has limited sensitivity. Peptide nucleic acids (PNA)-mediated PCR clamping method is a newly introduced method for analyzing EGFR mutations with increased sensitivity and stability. Methods: A total of 71 NSCLC patients were analyzed for EGFR mutations using the PNA-mediated PCR clamping technique. Sixty-nine patients were analyzed for clinicopathologic correlation with EGFR genotype; 2 patients with indeterminate results were excluded. In order to determine EGFR-TKI drug response, 57 patients (42 gefitinib, 15 erlotinib) were included in the analysis. Results: The EGFR mutation rate was 47.8%. Being female, a non-smoker, and having adenocarcinoma were favorable clinicopathologic factors, as expected. However, more than a few smokers (33.3%), male (28.1%), and patients with non-adenocarcinoma (28.6%) had the EGFR mutation. Having a combination of favorable clinicopathologic factors did not increase the EGFR mutation rate significantly. Drug response to EGFR-TKIs showed significant differences depending on the EGFR genotype; ORR was 14.3% for wild type vs 69.0% for mutant type; DCR is 28.6% for wild type vs 96.6% for mutant type. The median EGFR-TKI treatment duration is 7.6 months for mutant type group and 1.4 months for wild type group. Conclusion: EGFR genotype determined using the PNA-mediated PCR clamping method is significantly correlated with the clinical EGFR-TKI responses and PNA-mediated PCR.

• Tuberculosis and Respiratory Diseases
• /
• 제74권1호
• /
• pp.15-22
• /
• 2013

Background: Differentiating cardiogenic pulmonary edema from other bilateral lung diseases such as pneumonia is frequently difficult. We conducted a retrospective study to identify predictors for cardiogenic pulmonary edema and non-cardiogenic causes of bilateral lung infiltrates in chest radiographs. Methods: The study included patients who had newly developed bilateral lung infiltrates in chest radiographs and patients who underwent echocardiography. Cases were divided into two groups based on the echocardiographic findings: the cardiogenic pulmonary edema group and the non-cardiogenic group. Clinical characteristics and basic laboratory findings were analyzed to identify predictors for differential diagnosis between cardiogenic and non-cardiogenic causes of bilateral chest infiltrates. Results: We analyzed 110 subjects. Predictors of cardiogenic pulmonary edema were higher brain natriuretic peptide (BNP) levels, lower C-reactive protein (CRP) levels on the day of the event (<7 mg/dL), age over 60 years, history of heart disease, and absence of fever and sputum. CRP on the day of the event was an independent factor to differentiate cardiogenic and non-cardiogenic causes of newly developed bilateral chest infiltrates. Also, the validity was comparable to BNP. Conclusion: Clinical symptoms (sputum and fever), medical history (dyslipidemia and heart disease), and laboratory findings (BNP and CRP) could be helpful in the differential diagnosis of patients with acute bilateral lung infiltrates in chest radiographs.