• Bulletin of the Korean Chemical Society
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• 제29권2호
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• pp.479-482
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• 2008

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.62-63
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• 2005

• International Journal of Industrial Entomology and Biomaterials
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• 제37권1호
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• pp.15-20
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• 2018

Most proteins produced in the endoplasmic reticulum (ER) of eukaryotic cells fold via disulfide formation (oxidative folding). Oxidative folding is catalyzed by protein disulfide isomerase (PDI) and PDI-related ER protein thiol disulfide oxidoreductases (ER oxidoreductases). In yeast and mammals, ER oxidoreductin-1s (ERO1s) supply oxidizing equivalent to the active centers of PDI. We previously identified and characterized the ERO1 of Bombyx mori (bERO1) as a thioredoxin-like protein that shares primary sequence homology with other ERO1s. Here we compare the reactivation of inactivated rRNase and sRNase by bERO1, and show that bERO1 and bPDI cooperatively refold denatured RNase A. This is the first result suggesting that bERO1 plays an essential role in ER quality control through the combined activities of bERO1 and bPDI as a catalyst of protein folding in the ER and sustaining cellular redox homeostasis.

• 한국양식학회지
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• 제11권3호
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• pp.327-335
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• 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.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.235-242
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• 1999

We investigated the growth-inhibitory mechanism of Helicobacter pylori by omeprazole (OMP) and its activated sulfenamide (OAS). Using dithiothreitol (DTT) and 5,5'-dithio-bis[2-nitrobenzoic acid] (DTNB; Ellman's reagent), we first determined the relationship between the binding capacity of these compounds to H. pylori membrane and its significance to membrane P-type ATPase activity. After incubation of the intact H. pylori cells with either OMP or OAS, the residual quantity of free SH-groups on the cell membrane was measured, and, the resulting values were plotted as a function of time. From this experiment, we found that there was a considerable difference in the membrane-binding rates between OMP and OAS. At neutral pH, the disulfide bond formation on H. pylori membrane was completed within 2 min of incubation of the intact cells with OAS. By OMP, however, it was gradually formed, exceeding 10 min of incubation for completion, whereby, the extent of P-type ATPase inhibition appeared to be proportional to the disulfide forming rate. From this data, it was suggested that the disulfide formation might directly affect enzyme activity. Since OMP per se cannot yield a disulfide bond with cysteine, it is predicted that the enzyme inactivation must be caused by the OAS form. Accordingly, we postulated that, under the neutral pH, OMP could be converted to OAS in the course of transport. By extrapolating the inhibitory slopes, we could evaluate K₁ values, relating to their minimal inhibitory concentrations (MICs) for H. pylori growth. In these MIC ranges, H. pylori uptake or vesicular export of nutrients such as peptides were totally prohibited, but their effect in Escherichia coli were negligible. From these observations, we strongly suggest that the P-type ATPase activity is essential for the survival of H. pylori cells in particular.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.886-889
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• 2001

C-terminus specific immobilization often results in a increased structural stability resistant to various denaturation factors. In order to elucidate the immobilization effect on the c-terminus in molecular level, we made over 200 protein data set from Protein Data Bank(PDB), analyzed c-terminus structure of each protein, and investigated the structural relationship with the stabilizing factors such as hydrogen bond, ion pairs, cation pi, disulfide bond, solvation free energy, surface area, flexibility and so on.

• 생명과학회지
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• 제20권6호
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• pp.853-860
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• 2010

DevSR two-component system은 Mycobacterium smegmatis의 redox sensing에 관련된 주요한 regulatory system이다. DevSR system은 DevS histidine kinase와 DevR response regulator로 구성되어 있다. 저산소 조건에서 DevS histidine kinase는 활성화되어 DevR response regulator를 인산화 시키고, 인산화된 DevR response regulator는 DevR regulon의 transcriptional activator로 작용한다. DevS의 kinase activity는 DevS의 N-terminal에 위치한 GAF domain에 존재하는 heme의 ligand-binding state에 의해 결정된다. 본 연구에서는 C-terminal kinase domain의 redox-responsive cysteine (C547)이 DevS kinase activity의 redox-dependent control과 연관이 있음을 밝혔다. 산소가 존재할 때, C547 residue 사이의 disulfide bond의 형성은 DevS kinase activity를 불활성화 시킨다. $\beta$-mercaptoethanol과 dithiothreitol과 같은 환원제를 이용하여 산화된 DevS를 환원시켰을 때, DevS kinase activity가 복원된 것이 관찰되었다. 또한, C547을 alanine으로 치환했을 때, M. smegmatis의 DevS의 sensory 기능을 부분적으로 손상되는 것이 complementation 실험을 통해 in vivo 상에서 증명되었다.

• BMB Reports
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• 제43권1호
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• pp.23-28
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• 2010

Binary toxin consisting of BinA and BinB from Bacillus sphaericus is toxic to mosquito larvae. BinB is responsible for specific binding to the larval gut cell membrane while BinA is crucial for toxicity. To investigate functional role of cysteine in BinB, three cysteine residues at positions 67, 161, and 241 were replaced by alanine or serine. Mutations at these positions did not affect protein production and overall structure of BinB. These cysteine residues are not involved in disulfide bond formation between BinB molecules. Mosquito-larvicidal assays revealed that C67 and C161 are essential for toxicity, whereas C241 is not. Mutations at C67 and C161 resulted in weaker BinA-BinB interaction. The loss of toxicity may be due to the reduction of interactions between BinA and BinB or BinB and its receptor. C67 and C161 could also play a part during conformational changes or internalization of the binary toxin into the target cell.

• 대한금속재료학회지
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• 제46권9호
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• pp.604-608
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• 2008

The layered compounds vanadium disulfide($VS_2$) and vanadium dioxide($VO_2$) intercalated with Li are investigated for using the Discrete Variational $(DV)-X{\alpha}$ molecular orbital method. The chemical bonding properties of the atoms were examined by bond overlap population of electronic states. The plot of density of states supports the covalent bonding properties by showing the overlap between the atoms. There is a strong tendency of covalent bonding between V-S and V-O. The intensity of covalent bonding of $VS_2$ is stronger than $VO_2$. The net charge of $LiVO_2$ is higher than that of $LiVS_2$. This results of the calculation of $VO_2$ and $VS_2$ indicate that $(DV)-X{\alpha}$ method can be widely applied in the new practical materials.

• Archives of Pharmacal Research
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• 제22권5호
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• pp.459-463
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• 1999

The effects of the hindered and non-hindered water soluble long-chain disulfide bonds on the stability and cytotoxicity of the ricin A chain (RTA) immunotoxin were examined. The RTA immunotoxins were prepared with the Fab fragments of anti-common acute lymphoblastic leukemia antigen (CALLA) monoclonal antibody (Fab-RTA) using sulfosuccinimidyl-6-[(-methyl-(-2-pyridyldithio)toluamido]toluamido]hexanoate (S-LC-SMPT) and sulfosuccinimidyl-6-[3-(2-pyridyldithio-propionamido]hexanoate (S-LC-SPDP). The prepared Fab-RTA immunotoxins were evaluated for their conjugation yield, immunoreactivity, thermal and disulfide bond stability and cytotoxicity. The conjugation yield of the Fab-RTA immunotoxin from the water soluble long chain crosslinking agents, S-LC-SMPT and S-LC-SPDP, were comparable. Both Fab-RTA immunotoxins exhibited a similar immunoreactivity and thermal stability in aqueous solution. However, S-LC-SMPT -mediated Fab-RTA, sterically hindered, showed an enhanced disulfide bond stability in vitro over S-LC-SPDP mediated one. In the cytotoxicity against antigenic cell Daudi, the S-LC-SMPT -mediated RTA immunotoxin maintained a comparable cytotoxicity, compared with S-LC-SPDP mediated Fab-RTA immunotoxin.