• 한국미생물·생명공학회지
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• 제33권4호
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• pp.319-321
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• 2005

본 연구진은 phage display peptide library로부터 $TiO_{2}$ nanoparticle에 binding 하는 peptide를 선별하여 보고한바 있다. 이 중의 하나인 PEP9을 선택하여 alanine scanning mutagenesis를 통하여 mutant peptide를 display하는 phage를 제작하여 $TiO_{2}$에의 binding을 조사하였다. 그 결과, 4번 위치의 proline이 alanine으로 치환된 peptide의 경우 binding activity가 $10\%$로 감소하였고, 2번 valine, 3번 serine, 5번 isoleucine의 치환 peptide는 binding이 $40\%$로 감소하였다. 이러한 사실로 미루어볼 때, PEP9과 $TiO_{2}$ nanoparticle의 결합에는 2, 3, 4, 5번의 아미노산이 만들어내는 3차원적 구조가 중요한 역할을 하는 것으로 결론 내릴 수 있었다.

• Archives of Pharmacal Research
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• 제20권1호
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• pp.80-84
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• 1997

Substituted cinnamoyl-tyramine derivatives were synthesized by DCC-coupling of substituted cinnamic acid with tyramine or tyramine methyl-1-ether to evaluate PAF-receptor binding antagonistic activities and inhibitory activities on PAF-induced platelet aggregation with interest on structure-activity relations. The results show that 3,4-dimethoxy-cinnamoyl tyramine-amide or its methyl ether have significant PAF-receptor binding antagonistic activity and platelet anti-aggregatory activities.

• Bulletin of the Korean Chemical Society
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• 제17권11호
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• pp.1018-1022
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• 1996

Adenosine deaminase (ADA) has been utilized as the label in devising a potentiometric homogeneous assay for riboflavin and riboflavin binding protein (RBP). The proposed homogeneous assay method employs an ADA-biotin conjugate as the signal generator and an avidin-riboflavin conjugate as the signal modulator in the solution phase. The catalytic activity of the ADA-biotin conjugate is inhibited in the presence of an excess amount of the avidin-riboflavin conjugate, and the observed inhibition is reversed in an amount proportional to the concentration of RBP added. When the analyte riboflavin is added to this mixture of ADA-biotin, avidin-riboflavin and RBP, the activity of the enzyme conjugate is re-inhibited in an amount proportional to the concentration of riboflavin. Since the enzyme label used in this system is ADA, an ammonia-producing enzyme, a potentiometric rather than photometric detection scheme is used to monitor the enzymatic activity in the assay.

• Archives of Pharmacal Research
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• 제15권2호
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• pp.146-151
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• 1992

The aim of this study was to evaluate capability of pertussis toxin (PT) to active mouse macrophages. The investigations were undertaken to determine whether the role played by this toxin required the A-protomer of the toxin to ADP-ribosylate a guanine nucleotide binding protein (a class I activity) or was dependent on the binding of B-oligomer of the toxin to the surface of target cells (a Class II activity). The results of these experiments have established that the mechanism of macrophage activation with PT seems to be dependent upon a Class II activity of the toxin.

• 통합자연과학논문집
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• 제6권4호
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• pp.234-243
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• 2013

N-terminal kinase-like (NTKL) protein was initially identified as a protein binding to protein kinase B (PKB, also known as Akt). Though NTKL-BP1 (NTKL-binding protein 1) has been identified as an NTKL binding protein, its functions related to binding have not yet been elucidated. Here, a new alternative spliced variant of NTKL and its association with integrin ${\beta}1$ is described, in addition to the kinase activity of NTKL and its substrate candidates. Although the phosphorylation of the candidates must be further confirmed using other experimental methods, the observation that NTKL can phosphorylate ROCK1, DYRK3, and MST1 indicates that NTKL may act as a signaling protein to regulate actin assembly, cell migration, cell growth, and to facilitate differentiation and development in an integrin-associated manner.

• BMB Reports
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• 제37권6호
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• pp.709-714
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• 2004

The wild-type repressor CI of temperate mycobacteriophage L1 and the temperature-sensitive (ts) repressor CIts391 of a mutant L1 phage, L1cIts391, have been separately overexpressed in E. coli. Both these repressors were observed to specifically bind with the same cognate operator DNA. The operator-binding activity of CIts391 was shown to differ significantly than that of the CI at 32 to $42^{\circ}C$. While 40-95% operator-binding activity was shown to be retained at 35 to $42^{\circ}C$ in CI, more than 75% operator-binding activity was lost in CIts391 at 35 to $38^{\circ}C$, although the latter showed only 10% less binding compared to that of the former at $32^{\circ}C$. The CIts391 showed almost no binding at $42^{\circ}C$. An in vivo study showed that the CI repressor inhibited the growth of a clear plaque former mutant of the L1 phage more strongly than that of the CIts391 repressor at both 32 and $42^{\circ}C$. The half-life of the CIts391-operator complex was found to be about 8 times less than that of the CI-operator complex at $32^{\circ}C$. Interestingly, the repressor-operator complexes preformed at $0^{\circ}C$ have shown varying degrees of resistance to dissociation at the temperatures which inhibit the formation of these complexes are inhibited. The CI repressor, but not that of CIts391, regains most of the DNA-binding activity on cooling to $32^{\circ}C$ after preincubation at 42 to $52^{\circ}C$. All these data suggest that the 131st proline residue at the C-terminal half of CI, which changed to leucine in the CIts391, plays a crucial role in binding the L1 repressor to the cognate operator DNA, although the helix-turn-helix DNA-binding motif of the L1 repressor is located at its N-terminal end.

• 생명과학회지
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• 제30권11호
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• pp.1012-1020
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• 2020

생쥐의 가변부위가 인간의 정상부위에 연결되어 제조된 바이오시밀러 자연항체치료제인 레미케이드는 암괴사인자-알파(TNF-α)에 특이적인 항체로써 카이메릭 단일클론항체이며 류마티스 관절염치료를 위해 개발되었다. 바이오시밀러 레미케이드 항체의 생물학적 기능을 연구하기 위해 우리는 단백질 데이터 은행을 이용한 생물정보학 분석을 수행하여 레미케이드 자연항체와 암괴사인자-알파 항원간의 결합기작특징을 분석하였다. 자연항체를 생산하는 세포의 유전적 불안정성 때문에 레미케이드 항체생산이 제한되므로 우리는 중 사슬 가변부위를 다중펩타이드 링커에 의해 경 사슬 가변부위에 연결된 레미케이드 ScFv항체(Remicade)를 제조하였다. 더욱이 더 높은 생산과 더 높은 항원결합력을 위해 레미케이드 ScFv를 leucine zipper에 융합시켰다. Remicade와 RemicadeScZip ScFv는 대장균에서 발현되었고 Ni⁺-NTA-아가로스 컬럼으로 정제하였다. 정제된 단백질들은 예상한대로 sodium dodecyl sulfate-polyacrylamide electrophoresis에서 28.80 kDa과 33.96 kDa을 나타내었다. Remicade는 ELISA, western blot에서 TNF-α 항원에 대한 결합력이 관찰되지 않았으나 RemicadeScZip은 항원결합력을 나타내었다. 추가적인 BLI분석으로 RemicadeScZip의 TNF-α 항원에 대한 결합력을 재확인시켜주었으며 이 결과는 Leucine zipper가 레미케이드 ScFv의 접힘을 안정화시키고 TNF-α 항원에 대한 결합력을 개선시켰음을 제시해주고 있다.

• Biomolecules & Therapeutics
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• 제23권5호
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• pp.479-485
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• 2015

This study was performed to investigate the sedative-hypnotic activity of ${\gamma}$-aminobutyric acid (GABA)-enriched fermented marine organisms (FMO), including sea tangle (FST) and oyster (FO) by Lactobacillus brevis BJ20 (L. brevis BJ20). FST and FO were tested for their binding activity of the $GABA_A$-benzodiazepine and 5-$HT_{2C}$ receptors, which are well-known molecular targets for sleep aids. We also measured the sleep latency and sleep duration during pentobarbital-induced sleep in mice after oral administration of FST and FO. In $GABA_A$ and 5-$HT_{2C}$ receptor binding assays, FST displayed an effective concentration-dependent binding affinity to $GABA_A$ receptor, similar to the binding affinity to 5-$HT_{2C}$ receptor. FO exhibited higher affinity to 5-$HT_{2C}$ receptor, compared with the $GABA_A$ receptor. The oral administration of FST and FO produced a dose-dependent decrease in sleep latency and increase in sleep duration in pentobarbital-induced hypnosis. The data demonstrate that FST and FO possess sedativehypnotic activity possibly by modulating $GABA_A$ and 5-$HT_{2C}$ receptors. We propose that FST and FO might be effective agents for treatment of insomnia.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2629-2634
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• 2013

Fisetin is a naturally occurring flavonoid with some anti-cancer and anti-inflammation capabilities. In this study, we perform docking studies between human c-Jun N-terminal kinase 1 (JNK 1) and fisetin and proposed a binding model of fisetin and JNK 1, in which the hydroxyl groups of the B ring and oxygen at the 4-position of the C ring play key roles in binding interactions with JNK. Fluorescence quenching and saturation-transfer difference (STD) NMR experiments showed that fisetin exhibits good binding affinity to JNK, $1.32{\times}10^8M^{-1}$. The anti-inflammatory activity of fisetin was also investigated. Fisetin significantly suppressed tumor necrosis factor, the NO production, and macrophage inflammatory cytokine release in LPS-stimulated RAW264.7 mouse macrophages. We found that the anti-inflammatory cascade of fisetin was mediated through the JNK, and cyclooxygenase (COX)-2 pathways. Our findings suggest the potential of fisetin as an anti-inflammatory agent.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.329-333
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• 2005

This study was designed to investigate the stability of a lipase fused with a cellulose­binding domain (CBD) to cellulase. The fusion protein was derived from a gene cluster of a CBD fragment of a cellulase gene in Trichoderma hazianum and a lipase gene in Bacillus stearother­mophilus L1. Due to the CBD, this lipase can be immobilized to a cellulose material. Factors affecting the lipase stability were divided into the reaction-independent factors (RIF), and the re­action-dependent factors (RDF). RIF includes the reaction conditions such as pH and tempera­ture, whereas substrate limitation and product inhibition are examples of RDF. As pH 10 and $50^{\circ}C$ were found to be optimum reaction conditions for oil hydrolysis by this lipase, the stability of the free and the immobilized lipase was studied under these conditions. Avicel (microcrystal­line cellulose) was used as a support for lipase immobilization. The effects of both RIF and RDF on the enzyme activity were less for the immobilized lipase than for the free lipase. Due to the irreversible binding of CBD to Avicel and the high stability of the immobilized lipase, the enzyme activity after five times of use was over $70\%$ of the initial activity.