• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2649-2655
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• 2010

$PKC{\delta}$-catalytic V5 Heptapeptide (FEQFLDI, FP7) interacts with heat shock protein 27 (HSP27) and inhibits HSP27-mediated resistance to cell death against various stimuli including radiation therapy. Here, we prepared radio-iodinated heptapeptide and further investigated its uptake properties in HSP27 expression cells. Peptide sequence of FP7 and a negative control peptide (WSLLEKR, QP7) was modified by substituting their C-terminus residue to tyrosine (FP6Y and QP6Y) to label radio-iodine. Iodinated peptides were confirmed by LC mass analysis with cold iodine reaction mixture. Accumulation of [$^{125}I$]iodo-FP6Y and [$^{125}I$]iodo-QP6Y in NCI-H1299 cell line, with higher level of HSP27, and NCI-H460 cell line, with lower level of HSP27, was measured by NaI(Tl) scintillation counter. The modification of substituting C-terminus residue of FP7 to tyrosine (FP6Y) did not affect its interaction with HSP27. Accumulation of [$^{125}I$]iodo-FP6Y in NCI-H1299 cells was 3 fold higher than in NCI-H460 cells. The novel radio-iodinated FP6Y would be used as a tracer for targeting HSP27 protein.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.115-120
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• 2006

To convert the soybean curd residue (SCR) to functional food ingredient, alkaline fermentation of SCR was performed by Bacillus firmus NA-1 and Bacillus subtilis GT-D for 22 hr at $42^{\circ}C$. The micronized full-fat soy flour (MFS) was fortified to reduce the moisture content as well as to supply protein source. The mucilage and flavor productions in the fermented SCR were enhanced by the fortification of $20\%$ MFS. The peptide production from the SCR fermented with B. subtilis GT-D substantially increased when judged by the detectable amount of tyrosine $(480\;mg\%)$. The production of fibrinolytic enzyme was increased by the fermentation for 22 hr, indicating the relative activity of $62\%$ (B. firmus NA-1) and $47\%$ (B. subtilis GT-D), respectively. The SCR fermented by B. firmus NA-1 and B. subtilis GT-D indicated the consistency of $1.95\;Pa{\cdot}s^n\;and\;0.21\;Pa{\cdot}s^n$, respectively. After freeze-drying, the protease activity (615 unit/g) and a-amylase activity (180 unit/g) were obtained from SCR fermented by Bacillus firmus NA-1 and Bacillus subtilis GT-D, respectively.

• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.560-566
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• 2013

In this research we extracted water-soluble collagen peptide from flatfish skin and compared it with commercially available collagen peptide extracted from Tilapia scale currently placed on the market in the aspect of physiochemical property. The physical property and nutritional components of FSCP appeared almost similarly to those of TSCP, and also in calorie, FSCP marking 3.82 Kcal showed no differences from TSCP marking 3.84 Kcal. As for forming amino acids, in aspartic acid, serine, histidine, tyrosine, methionine, FSCP had higher content than TSCP, but in OH-proline, proline and alanine FSCP had lower content than TSCP. Especially the content of essential amino acids of FSCP marked 22.74% with a higher content compared with 13.64% of TSCP. In the distribution of molecular weight FSCP with 1,000 Da showed comparatively low compared with TSCP, and in emulsion property and stability FSCP and TSCP showed similar excellent trend.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.81-81
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• 1995

It is well known that Src Homology 2(SH2) domain in many intracellular signal transduction proteins is very important. The domain has about 100 amino acid residues and bind phosphotyrosine-containing peptide with high affinity and specificity. Lck SH2 domain is a Src-like, lymphocyte-specific tyrosine kinase. An 11-residue phosphopeptide derived from the hamster polvoma middle-T antigen, EPQp YEEIPIYL, binds with an 1 nM dissociation constant to Lck SH2 domain. And it is known that the phosphotyrosine and isoleucine residues of the peptide are tightly bound by two well-defined pockets on Lck SH2 domain's surface. To investigate the conformational changes during complexation of SH2 domain with phosphopeptide we have performed the molecular dynamics simulation for Lck SH2 domain with peptide and peptide-free form at look in aqueous solution. More than 3000 water molecules were incorporated to solvate Lck SH2 domain and peptide. Periodic boundary condition has been applied in molecular dynamics simulation. Data analysis with the results of that simulation shows that the phosphopeptide makes primary interaction with the Lck SH2 domain at six central residues, The comparison of the complexed and uncomplexed SH2 domain structures in solution has revealed only relatively small change. But the hydrophilic and hydrophobic pockets in the protein surface show the conformational changes in spite of the small structural difference between the complex and peptide-free forms.

• YAKHAK HOEJI
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• v.40 no.2
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• pp.193-201
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• 1996

In order to study the role of C-terminal aromatic region of T4 endonuclease V in the interaction with substrate DNA, NMR and Fluorescence spectrum were recorded. Analysis of flu orescence emission spectra showed that C-terminal region of T4 endonuclease V is in or very near the binding site. In the HSQC spectrum of $^{15}N$-Tyr-labeled T4 endonuclease V*DNA complex, the broadening of a peak was observed. It is presumed that this peak corresponds to one among three tyrosine residues which belong to the WYKYY segment of C-terminal region of T4 endonuclease V. Interactions of peptide fragments consisting of C-terminal residues of T4 endonuclease V with DNAs(TT-, T^T-DNA) were investigated by NMR and Fluorescence experiment. The results suggest that two peptide fragments themselves bind to DNAs and their binding pattern is not an intercalation mode.

• Food Science of Animal Resources
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• v.25 no.3
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• pp.340-343
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• 2005

The objective of this work was to study separation of short peptide (glycine-tyrosine) by using supported liquid membranes (SLMs) containing Aliquat as a cationic carrier, In the present investigation, the influence of pH of donor phase, concentrations of carrier and salt concentrations of acceptor phase on separation flux rate were investigated. Below pH 7.0 the flux rate was not affected by NaCl concentration or carrier concentration. However, the rate was increased significantly above pH 7.0. The rate with Hossain's SLM(H-SLM) containing $20\%$ Aliquat was about 3-fold higher with pH 9.0 at 0.25 M NaCl and 10-fold higher with pH 8.0 at 1.0 M NaCl than that with Duggan's SLM(D-SLM) containing $8\%$ Aliquat respectively. Furthermore, the rate with H-SLM was 10-fold higher at 1.0 M NaCl than the rate with 0.25 M NaCl, In conclusion, it would appear that the rate of separation was facilitated by using high salt concentrations together with high carrier concentrations above pH 7.0.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.275-284
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• 1984

In order to study the flavor quality of Chungkookjang, the changes in nitrogenous compounds, nucleotides and their related compounds, free amino acids, amino acid composition and fatty acids were analysed during Chungkookjang Koji fermentation. Koji was prepared with Bacillus natto isolated from Japanese natto. Insoluble nitrogenous was rapidly decreased, whereas PAA (peptide, amino, ammonia) nitrogen were slightly increased during the fermentation of Chungkookjang Koji. The content of extracted nitrogen and free amino acid nitrogen were rapidly increased until 48 hours fermentation of Chungkookjang Koji and then decreased. The contents of ADP, ATP, AMP and inosine in raw soybean were abundant. The contents of ADP, ATP and AMP were decreased while inosine and hypoxanthine were increased during the fermentation of Chungkookjang Koji. The free amino acids analyzed in this experiment were not changed in composition but changed in amounts during the fermentation of Chungkookjang Koji. The contents of alanine, valine, isoleucine and phenylalanine were continually increased during the fermentation of Chungkookjang Koji. The contents of lysine, histidine, arginine, glutamic acid, glycine, methionine and tyrosine were increased until 48 hours fermentation and then decreased gradually. The increase in the contents of aspartic acid, threonine, serine, proline and cystine were fluctuated. In raw soybean, amino acid composition such as glutamic acid, serine and proline were dominant amino acid and amounts those were 63.8% of the total amino acids. The contents of aspartic acid, proline, glycine, alanine, cystine, leucine and tyrosine were continually decreased during the fermentation of Chungkookjang Koji, arginine and methionine were increased until 48 hours fermentation of Chungkookjang Koji and then decreased gradually. The increase of threonine and serine were fluctuated. Eight kinds of fatty acids were detected from raw soybean, but 10 kinds of fatty acids detected from Chungkookjang Koji. Palmitic, oleic and linoleic acid were identified as the major fatty acid of raw soybean and Chungkookjang Koji, and amounts of those were estimated above 80% of the total fatty acids.

• 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.

• Tuberculosis and Respiratory Diseases
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• v.83 no.1
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• pp.51-60
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• 2020

Background: Programmed death-ligand 1 (PD-L1) expression is tested by immunohistochemistry (IHC)-22C3, SP263, and SP142. The aim of this study is to evaluate the correlation among the three methods of PD-L1 IHC in non-small cell lung cancer (NSCLC) and clinical significance of PD-L1 expression in lung adenocarcinoma with an epidermal growth factor receptor (EGFR)-tyrosine kinase domain mutation. Methods: The results of 230 patients who were pathologically confirmed as having NSCLC; tested using PD-L1 IHC 22C3, SP263, and SP142 methods; and evaluated via the peptide nucleic acid clamping method to confirm EGFR mutation, were analyzed in this study. Results: 164 patients underwent both the SP263 and 22C3 tests. There was a significant positive correlation between the outcomes of the two tests (Spearman correlation coefficient=0.912, p<0.001), with a derived regression equation as follows: 22C3=15.2+0.884×SP263 (R²=0.792, p<0.001). There was no relationship between the expression of PD-L1 and clinical parameters, including EGFR-tyrosine kinase inhibitor (TKI) mutation. The PD-L1 expression in patients treated with EGFR-TKI yielded a 2-month-shorter progression period than that in the PD-L1-negative group. However, this did not reach statistical significance (PD-L1<1% vs. PD-L1≥1%, 10 months vs. 8 months). Conclusion: The results of the 22C3 and those of SP263 methods were in good correlation with one another. Since the PD-L1 expression is not influenced by the EGFR mutation, it is necessary to perform a PD-L1 test to set the treatment direction in the patients with EGFR-mutant NSCLC.

• Tuberculosis and Respiratory Diseases
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• v.74 no.3
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• pp.129-133
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• 2013

The presence of epidermal growth factor receptor (EGFR ) mutation is a prognostic and predictive marker for EGFR-tyrosine kinase inhibitor (TKI) therapy. However, inevitably, relapse occurs due to the development of acquired resistance, such as T790M mutation. We report a case of repeated responses to EGFR-TKIs in a never-smoked woman with adenocarcinoma. After six cycles of gemcitabine and cisplatin, the patient was treated by gefitinib for 4 months until progression. Following the six cycles of third-line pemetrexed, gefitinib retreatment was initiated and continued with a partial response for 6 months. After progression, she was recruited for an irreversible EGFR inhibitor trial, and the time to progression was 11 months. Although EGFR direct sequencing on the initial diagnostic specimen revealed a wild-type, we performed a rebiopsy from the progressed subcarinal node at the end of the trial. The result of peptide nucleic acid clamping showed L858R/L861Q.