• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3675-3681
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• 2011

Fusarium oxysporum, an important pathogen that mainly causes vascular or fusarium wilt disease which leads to economic loss. Disruption of gene encoding a heterotrimeric G-protein-${\beta}$-subunit (FGB1), led to decreased intracellular cAMP levels, reduced pathogenicity, colony morphology, and germination. The plant defense protein, Nicotiana alata defensin (NaD1) displays potent antifungal activity against a variety of agronomically important filamentous fungi. In this paper, we performed a molecular modeling and docking studies to find vital amino acids which can interact with various antifungal compounds using Discovery Studio v2.5 and GRAMMX, respectively. The docking results from FGB1-NaD1 and FGB1-antifungal complexes, revealed the vital amino acids such as His64, Trp65, Ser194, Leu195, Gln237, Phe238, Val324 and Asn326, and suggested that the anidulafungin is a the good antifungal compound.The predicted interaction can greatly assist in understanding structural insights for studying the pathogen and host-component interactions.

• BMB Reports
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• v.29 no.6
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• pp.519-524
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• 1996

Peptidylprolyl cis-trans isomerase (PPlase) catalyzes the cis-trans isomerization of prolyl peptide and facilitates the folding of cellular proteins and peptides. PPlase consists of two distinct immunophilins, each specifically binding to the immunosupressive drug cyclosporin A (CsA) or FK506, respectively. A PPlase was isolated and partially purified from porcine spleen. The molecular weight of porcine spleen PPlase was determined to be ~14,000 on the basis of SDS-PAGE. The purified enzyme was strongly inhibited by FK506, but not by CsA. The inhibition constant and the true concentration of enzyme preparations were determined by active site titration using the tight binding inhibitor FK506: $K_{i}=18.7$ nM and $E_{t}=172$ nM. The equilibrium ratio of conformer. [cis]/[trans], of prolyl peptide substrates (N-Suc-Ala-Xaa-Pro-Phe-p-NA) in anhydrous trifluoroethanol/LiCl solvent system varied from 0.24 to 0.85 depending on the nature of Xaa. Overall. in this solvent-salt system, the populations of the cis conformer of substrates in equilibrium are higher than in an aqueous solution so that the substantial error caused by high background absorption can be reduced. The reactivities of porcine spleen PPlase are shown to be highly sensitive to changes in the structure of substrates. Thus, $k_{cat}/K_m$ value for the most reactive substrate (Xaa Leu) is $4.007+10^{6}M^{1}s^{1}$ and, is 2,636 fold higher than that for the least reactive peptide substrate tested, Xaa=Glu.

• BMB Reports
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• v.46 no.3
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• pp.175-180
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• 2013

Cyt2Aa2 is a mosquito larvicidal and cytolytic toxin produced by Bacillus thuringiensis subsp. darmstadiensis. The toxin becomes inactive when isoleucine at position 150 was replaced by alanine. To investigate the functional role of this position, Ile150 was substituted with Leu, Phe, Glu and Lys. All mutant proteins were produced at high level, solubilized in carbonate buffer and yielded protease activated product similar to those of the wild type. Intrinsic fluorescence spectra analysis suggested that these mutants retain similar folding to the wild type. However, mosquito larvicidal and hemolytic activities dramatically decreased for the I150K and were completely abolished for I150A and I150F mutants. Membrane binding and oligomerization assays demonstrated that only I150E and I150L could bind and form oligomers on lipid membrane similar to that of the wild type. Our results suggest that amino acid at position 150 plays an important role during membrane binding and oligomerization of Cyt2Aa2 toxin.

• Journal of Korean Academy of Nursing
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• v.8 no.1
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• pp.85-98
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• 1978

This study was designed to investigate the elderly people's attitude toward death for the purpose of identifying the issues needed in the planning of health management and care activities for the aged. The total number of subjects in this study was 354 elderly people who were accommodated in house for elderly people (185) and school for elderly people (169). The scale for the attitude toward death of aged persons as an instrument of this study was mainly constructed with reference to Schneidman's attitude questioners toward death modified of adjust the Korean cultural characteristics and attitudes concerning death. Theresultsofthisstudywereasfollows: - 1. Out of total 45.8% of the respondents consider that death is a natural phenomena and ending of life. The responses on the meaning of death appeared differently : non-religions (48.1%) and oriental religions (50.3%) consider death as a natural phenomena however western religions (47.4%) consider that death is God's call. This difference was statistically significant. (x$^2$= 56.6419. df = 10. p<0.01). Respondents with a spouses (52.4%) think death is a natural phenomena opposed to respondent without spouses (33.3%). This was statistically significant. (x$^2$= 14.7134. df= 5 p<0.05). 2. Respondents in the house for aged persons (51.9%) replied. They do not wanted death because it meant a separation from their family as compared to those from school for aged persons (26.0%). 57.9% responded that they want to be told when death is confronted. 3. 51.2% of the respondents replied that the main factor to influence their attitude toward concept of death was the dying of their friends & relatives. 79.9% of respondents expressed that wished to die. The main reason for dying was economic shortage (28.3%). 4. 70.1% of the respondents want their body to be hurried while only 1.1% of the respondents want to donate their body to a medical research. 5. Over two thirds of the respondents replied that they do not believe in a life in heaven or that they will be rebirth. 6. The questioners of this study stimulated 56.8% of the respondents to feel that they should spend the leu of their life more effectively and 15.5% of the respondents felt it gave them the opportunity to think about their death seriously.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1733-1736
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• 2006

A new biologically active peptide with structural similarity to neuromedin N (NMN) has been isolated from extracts of visceral tissue of the African lungfish, Protopterus dolloi, using the rectum of the quail as the bioassay system. The primary structure of NMN-related peptide was established as Lys-Ala-Pro-Tyr-Ile-Leu-OH ([$Ala_2$]-NMN) and contained one substitution ($Ala_2\rightarrow$Ile) compared with the porcine NMN. [$Ala_2$]-NMN was found to have an excitatory effect on rectal muscle tissues of quail (Coturnix japonica), newt (Cynops pyrrhogaster) and black bass (Micropterus sulmoides). The threshold concentration of [Ala2]-NMN for contraction of C. japonica muscle was found to be approximately $10^-11$M. [$Ala_2$]-NMN showed contractile activities in the following order: C. japonica > C. pyrrhogaster > M. sulmoides. The identification of [Ala2]-NMN provides evidence that NMN family, hitherto confined to mammals, has a widespread occurrence in lungfish.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.816-822
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• 2005

Catharsius protease-2 (CPM-2) was isolated from the body of dung beetles, Catharsius molossus, using a three step purification process (ammonium sulfate fractionation, gel filtration on Bio-Gel P-60, and affinity chromatography on DEAE Affi-Gel blue). The purified CPM-2, having a molecular weight of 24 kDa, was assessed homogeneously by SDS-polyacrylamide gel electrophoresis. The N-terminal amino acid sequence of CPM-2 was composed of X Val Gin Asp Phe Val Glu Glu lie Leu. CPM-2 was inactivated by $Cu^{2+}\;and\;Zn^{2+}$ and strongly inhibited by typical serine proteinase inhibitors such as TLCK, soybean trypsin inhibitor, aprotinin, benzamidine, and ${\alpha}_1$-antitrypsin. However, EDTA, EGTA, cysteine, $\beta$-mercaptoethanol, E64, and elastatinal had little effect on enzyme activity. In addition, antiplasmin and antithrombin III were not sensitive to CPM-2. Based on the results of a fibrinolytic activity test, CPM-2 readily cleaved $A{\alpha}-$ and $B{\beta}$-chains of fibrinogen and fibrin, and y-chain of fibrinogen more slowly. The nonspecific action of the enzyme resulted in extensive hydrolysis, releasing a variety of fibrinopeptides of fibrinogen and fibrin. Polyclonal antibodies of CPM-2 were reactive to the native form of antigen. The ELISA was applied to detect quantities, in nanograms, of the antigen in CPM-2 protein.

• Molecules and Cells
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• v.41 no.6
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• pp.545-552
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• 2018

Spleen tyrosine kinase (SYK) is a cytosolic non-receptor protein tyrosine kinase. Because SYK mediates key receptor signaling pathways involving the B cell receptor and Fc receptors, SYK is an attractive target for autoimmune disease and cancer treatments. To date, representative oral SYK inhibitors, including fostamatinib (R406 or R788), entospletinib (GS-9973), cerdulatinib (PRT062070), and TAK-659, have been assessed in clinical trials. Here, we report the crystal structures of SYK in complex with two newly developed inhibitors possessing 4-aminopyrido[4,3-D]pyrimidine moieties (SKI-G-618 and SKI-O-85). One SYK inhibitor (SKI-G-618) exhibited moderate inhibitory activity against SYK, whereas the other inhibitor (SKI-O-85) exhibited a low inhibitory profile against SYK. Binding mode analysis indicates that a highly potent SYK inhibitor might be developed by modifying and optimizing the functional groups that interact with Leu377, Gly378, and Val385 in the G-loop and the nearby region in SYK. In agreement with our structural analysis, one of our SYK inhibitor (SKI-G-618) shows strong inhibitory activities on the ${\beta}$-hexosaminidase release and phosphorylation of SYK/Vav in RBL-2H3 cells. Taken together, our findings have important implications for the design of high affinity SYK inhibitors.

• Journal of Microbiology
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• v.39 no.2
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• pp.95-101
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• 2001

In an effort to develop an efficient expression and secretion system for heterologous proteins in Aspergilius nidulans, the PCR-amplified coding sequence for alkaline pretense (AlpA) of A. oryzae was cloned into a fungal expression vector downstream of A. nidulans aicA (alcohol dehydrogenase) promoter to yield pRAAlp. Transformation of A. nidulans with pRAAlp gave stable transformants harboring various copy numbers (3 to 10) of integrated alpA gene, from among which 6 representatives were selected. On a medium containing 0.8% ammonium sulfate that represses the expression of the host's own pretense, the alcA prumoter-controlled AlpA expression was strongly induced by threonine but repressed by glucose. The level of AlpA secretion was highest (approximately 666 mU/ml) in transformant ALP6 containing the largest copy number integrated alpA. However, the level of AlpA secretion was not necessarily proportional to the copy numbers of the integrated alpA genes. The N-terminal sequence or the secreted mature AlpA was determined to be Gly-Leu-Thr-Thr-Gln-Lys-Ser and its molecular mass to be approximately 34 kDa, indicating that AlpA is properly processed by the removal of 121 N-terminal amino acids.

• KSBB Journal
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• v.26 no.2
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• pp.151-156
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• 2011

For the development of functional food and cosmetics using the hot water extract of Undaria pinnatifida, the concentrations of vitamin, amino acid and element and activities of antioxidant and nitrite scavenging were investigated. The results are shown as follows: Vitamin C and E concentrations were 0.301 and 0.11 mg/100 g, respectively. Mineral concentrations were an order of Ca > Mg > K > Fe. The concentrations of total amino acids were an order of Glu > Ala > Val > Leu > Gly > Pro. Total phenol concentration and DPPH radical scavenging activity were increased with the increase of the concentration of extract. Especially, when the extract concentrationwas increased from 1.0 to 10.0 mg/mL, the total phenol concentration was increased from 0.043 to 0.125 OD 725 nm. DPPH radical scavenging activity at 50 mg/mL was 70.1%. The antioxidant activity of extract was stable in range of 80 to $140^{\circ}C$ and pH 3-9. The nitrite scavenging activity was increased with the decreaseof pH and the increase of it's extract concentration. Especially, it was 83.4% at 50 mg/mL (pH 1.2). These results showed that the hot water extract of U. pinnatifida can be applied to functional food and cosmetics.

• Biomolecules & Therapeutics
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• v.2 no.4
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• pp.303-309
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• 1994

The analysis of membrane receptors for hormones and neurotransmitters has progressed considerably by pharmacological and biochemical means and more recently through the use of specific antibodies. Two kinds of antibodies could be produced, one is from synthetic peptides and the other from proteins such as purified receptor. Anti-peptide antibodies gave some advantages; epitope is evident and also receptor purification in quantity is not prerequisite. It can be also applied to the study of receptor structure-activity relationship. The purpose of the present study was 1) to produce and characterize a polyclonal antibody against a synthetic $\beta$2-adrenergic receptor peptide(Phe-Gly-Asn-Phe-Trp-Cys-Phe-Trp-Thr-Ser-Ile-Asp-Val-Leu) and 2) to determine the effects of this antibody on the $\beta$-adrenergic receptor ligand interaction. The peptide sequence contains an amino acid residue such as Asp-113 which was identified as one of important component for receptor-ligand interaction in site-directed mutagenesis studies. Production of antibody was performed by immunization of rabbits through popliteal lymph node with the peptide coupled with Keyhole Limpet Hemocyanin (KLH). The titer of antibody against this peptide was 1 : 1000. The anti-peptide antibody was able to detect a 67 kDa protein band in western blot corresponding to the molecular weight of the $\beta$-adrenergic receptor in partially purified receptor fraction derived from guinea pig lung. The antisera inhibited the specific binding of [$^3$H]dihydroalprenolol to $\beta$-adrenergic receptor in a concentration-dependent manner. The results from this study suggest that the peptide sequence selected in the present study is important for the receptor ligand interaction.