• Applied Biological Chemistry
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• 제17권2호
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• pp.143-148
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• 1974

Aflatoxin $B_1$은 전자수용성(電子受容性)을 높여주는 염화아연(鹽化亞鉛) 존재하(存在下)에서 전자공여성분자(電子供與性分子)인 Benzene과 Charge-transfer Complex를 만들며, 그 생성기구(生成機構)는 Aflatoxin $B_1$이 염화아연(鹽化亞鉛)과 일차적(一次的)으로 배위결합(配位結合)된 화합물(化合物)을 거쳐, 이것이 Benzene과 결합(結合)하여 착물(錯物)을 형성(形成)한다. 이 착물(錯物)의 안정도상수(安定度常數) 즉(卽) 평형상수(平衡常數) 0.198 l/mole이었다. 따라서 Aflatoxin $B_1$은 약(弱)한 전자수용체(電子受容體)이나, Benzene 보다 강(强)한 전자공여체(電子供與體)와는 염화아연(鹽化亞鉛)이 존재(存在)하지 않아도 Charge-transfer Complex를 만들 수 있다는 가능성(可能性)을 제시(提示)해 주는 것이며, Tryptophane, Histidine과 같은 강(强)한 전자공여체(電子供與體)를 함유(含有)한 단백질(蛋白質) 또는 Guanine, Adenine과 같은 전자공여체(電子供與體)를 함유(含有)한 DNA등(等)과의 Aflatoxin $B_1$의 결합(結合)은 그 결합(結合) Mechanism으로서 Charge-transfer Complex 형성(形成)으로 이루어진다는 추정(推定)을 할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제9권5호
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• pp.604-612
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• 1999

A puc-deleted cell of Rhodobacter sphaeroides grows with a doubling time longer than 160 h under light-limiting photoheterotrophic (3 Watts [W]/㎡) conditions due to an absence of the peripheral light-harvesting B800-850 complex. A spontaneous fast-growing mutant, R. sphaeroides SK101, was isolated from the puc-deleted cells cultured photoheterotrophically at 3 W/㎡. This mutant grew with an approximately 40-h doubling time. The growth of the mutant, however, was indistinguishable from its parental strain during photoheterotrophic growth at 10 W/㎡ as well as during aerobic growth. The membrane of SK101 grown aerobically did not reveal the presence of any spectral complex, while the amounts of the B875 complex and photosynthetic pigments of SK101 grown anaerobiclly in the dark with dimethylsulfoxide (DMSO) were the same as those of the parental cell. These results indicate that the oxygen control of the photosynthetic complex formation remained unaltered in the mutant. The B875 complex of SK101 under light-limiting conditions was elevated by 20％ to 30％ compared with that of the parental cell, which reflected the parallel increase of the bacteriochlorophyll and carotenoid contents of the mutant. When the puc was restored in SK101, the B875 complex level remained unchanged, but that of the B800-850 complex increased. The mutated phenotype of SK101 was complemented with orfQ encoding a putative bacteriochlorophyll-mobilizing protein. Accordingly, it is proposed that the mutated OrfQ of SK101 should have an altered affinity towards the assembly factor specific to the most peripheral light-harvesting complex, which could be either the B875 or the B800-850 complex.

• Journal of Plant Biology
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• 제26권2호
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• pp.91-99
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• 1983

The formation of chlorophyll-protein complexes (CP-complexes) during the greening of rape cotyledons (Brassica napus cv. Yongdang) was investigated by the SDS-polyacrylamide gel electrophoresis. The total chlorophyll content and Chl a/b ratio were also determined. In addition, the effects of dark treatment on the CP-complex patterns during greening have been examined with respect to their photosynthetic electron transport activity. Greening has brought about the increasein total chlorophyll content and the decrease in Chl a/b ratio, but there have been no changes in Chl a/b ratio after 24 hrs of greening. The light-harvesting chlorophyll a/b-protein complex (LHCP-complex0 was predominant during the initial greening period. Thereafter, the amout of chlorophyll a-protein complex (CP I-complex) was gradually increased. Twenty-four-hr dark treatment immediately after illumination for 6 hrs and 12 hrs resulted in the increase of the Chl a/b ration and the CP I complex, otherwise the decrease of the LHCP-complex. The LHCP/CP I ratio was gradually decreased with further greening, and appeared no change after 48 hrs illumination. The investigation of the photosynthetic electron transport activity indicated that photosystem (PS) II activity (H2Olongrightarrowp-PD*＋FeCy**) did not change, but the activity of PS I was increased suddenly due to the dark treatment. The data suggests that the increase of CP I-complex may result in that of P-700, that is, the increase of PS I activity.

• Journal of Ginseng Research
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• 제41권2호
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• pp.209-214
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• 2017

Background: Both ginsenoside Re and B-complex vitamins are widely used as nutritional supplements. They are often taken together so as to fully utilize their antifatigue and refreshing effects, respectively. Whether actually a drug-nutrient interaction exists between ginsenoside Re and B-complex vitamins is still unknown. The objective of this study was to simultaneously investigate the effect of B-complex vitamins on the antifatigue activity and bioavailability of ginsenoside Re after their oral administration. The study results will provide valuable theoretical guidance for the combined utilization of ginseng and B-complex vitamins. Methods: Ginsenoside Re with or without B-complex vitamins was orally administered to mice to evaluate its antifatigue effects and to rats to evaluate its bioavailability. The antifatigue activity was evaluated by the weight-loaded swimming test and biochemical parameters, including hepatic glycogen, plasma urea nitrogen, and blood lactic acid. The concentration of ginsenoside Re in plasma was determined by liquid chromatography-tandem mass spectrometry. Results: No antifatigue effect of ginsenoside Re was noted when ginsenoside Re in combination with B-complex vitamins was orally administered to mice. B-complex vitamins caused to a reduction in the bioavailability of ginsenoside Re with the area under the concentration-time curve from zero to infinity markedly decreasing from $11,830.85{\pm}2,366.47h{\cdot}ng/mL$ to $890.55{\pm}372.94h{\cdot}ng/mL$. Conclusion: The results suggested that there were pharmacokinetic and pharmacodynamic drug-nutrient interactions between ginsenoside Re and B-complex vitamins. B-complex vitamins can significantly weaken the antifatigue effect and decrease the bioavailability of ginsenoside Re when simultaneously administered orally.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1801-1808
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• 2006

The interaction between whey carrier protein $\beta$-lactoglobulin type A and B (BLG-A and -B) and 2,2'-bipyridin n-hexyl dithiocarbamato Pd(II) nitrate (BPHDC-Pd(II)), a new heavy metal complex designed for anticancer property, was investigated by fluorescence spectroscopy combined with chemometry and circular dichroism (CD) techniques. A strong fluorescence quenching reaction of BPHDC-Pd(II) to BLG-A and -B was observed. Hence, BPHDC-Pd(II) complex can be bound to both BLG-A and -B, and quench the fluorescence spectra of the proteins. The quenching constant was determined using the modified Stern-Volmer equation. The binding parameters were evaluated by fluorescence quenching method. The results of binding study provided evidences presence of two and three sets of binding sites on the BLG-B and -A, respectively, for BPHDC-Pd(II) complex. Using fluorescence spectroscopy and chemometry, the ability of BLG-A and -B to form an intermediate upon interaction with BPHDC-Pd(II) complex was assessed. CD studies displayed that under influence of different concentrations of BPHDC-Pd(II) complex, the regular secondary structure of BLG-B had no significant changes, whereas for BLG-A a transition from $\alpha$-helix to $\beta$-structure was appeared. The results for both of BLG-A and -B displayed that BPHDC-Pd(II) complex can induce a conformational transition from the native form to an intermediate state with a slightly opened conformation, which is detectable with chemometry analyses.

• 한국전자파학회논문지
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• 제12권5호
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• pp.686-693
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• 2001

본 논문에서는 대전력 증폭기의 비선형 전달 특성을 나타내는 Carrier Complex Power Series를 유도하였고, 이 전달함수를 이용하여 대전력 증폭기를 선형화하기 위한 전치 왜곡기의 비선형 전달 특성을 유도하고 구현하였다. 측정 시료로 제작된 IMT-2000 기지국 송신 대역 대전력 증폭기의 이득은 34.6 dB이고 P$_{1dB}$가 35.4 dBm이다. Inverse Carrier Complex Power Series를 이용한 전치 왜곡기를 제작하고, 대전력 증폭기에 부착하여 주파수가 각각 2.1375 GHz와 2.1425 GHz($\Delta$f=5 MHz)인 2-tone 신호의 출력이 25.43 dBm/tone일 때 17 dB의 개선 특성을 얻었다.다.

• Journal of Plant Biology
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• 제36권3호
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• pp.281-284
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• 1993

A karyotype of cytotype BB plant in Scilla scilloides Complex was established and the frequency of B-chromosomes were investigated. Chromosome complements of BB genome were composed of five pairs of subtelocentric and four pairs of metacentric chromosomes. Chromosome 1 has satellite with nucleolar organizer. Polymorphism was found in chromosome 2. The karyotype of cytotype BB will be available for analysis of genome composition in various cytotypes of S. scilloides Complex. The frequency of B-chromosome was 78.6%. Numbers of B-chromosome ranged from 1 to 4 and plants with 2B-chromosomes were predominant (57.2%). Two type of B-chromosomes, F and F', were found; F is a large iso-chromosome and F' a small one.

• The Korean Journal of Physiology and Pharmacology
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• 제27권5호
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• pp.427-436
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• 2023

Mitotic arrest deficient 2 like 2 (Mad2L2, also known as Mad2B), the human homologue of the yeast Rev7 protein, is a regulatory subunit of DNA polymerase ζ that shares high sequence homology with Mad2, the mitotic checkpoint protein. Previously, we demonstrated the involvement of Mad2B in the cisplatin-induced DNA damage response. In this study, we extend our findings to show that Mad2B is recruited to sites of DNA damage in human cancer cells in response to cisplatin treatment. We found that in undamaged cells, Mad2B exists in a complex with Polζ-Rev1 and the APC/C subunit Cdc27. Following cisplatin-induced DNA damage, we observed an increase in the recruitment of Mad2B and Cdc20 (the activators of the APC/C), to the complex. The involvement of Mad2B-Cdc20-APC/C during DNA damage has not been reported before and suggests that the APC/C is activated following cisplatin-induced DNA damage. Using an in vitro ubiquitination assay, our data confirmed Mad2B-dependent activation of APC/C in cisplatin-treated cells. Mad2B may act as an accelerator for APC/C activation during DNA damage response. Our data strongly suggest a role for Mad2B-APC/C-Cdc20 in the ubiquitination of proteins involved in the DNA damage response.

• 대한수학회지
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• 제32권3호
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• pp.471-482
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• 1995

A complex n-dimensional Kaehlerian manifold of constant holomorphic sectional curvature c is called a comples space form, which is denoted by $M_n(c)$. A complete and simply connected complex space form consists of a complex projective space $P_nC$, a complex Euclidean space $C^n$ or a complex hyperbolic space $H_nC$, according as c > 0, c = 0 or c < 0. The induced almost contact metric structure of a real hypersurface M of $M_n(c)$ is denoted by $(\phi, \zeta, \eta, g)$.

• Journal of Pharmaceutical Investigation
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• 제41권2호
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• pp.95-102
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• 2011

An amphiphilic cationic branched methoxy poly (ethylene glycol)-branched polyethylenimine - poly(L-phenylalanine) (mPEG-bPEI-pPhe) block copolymer was successfully synthesized by ring-opening polymerization (ROP) of N-carboxyanhydride of L-phenylalanine (Phe-NCA) with mPEG-bPEI for the preparation of more stable polyelectrolyte complex (PEC) included a hydrophobic interaction. mPEG-bPEI was firstly prepared by the coupling of mPEG and bPEI using hexamethylene diisocyanate (HMDI). The structural properties of mPEG-bPEI-pPhe copolymers were confirmed by $^1H$ NMR. The copolymers exhibited a self-assemble behavior in water above critical aggregate concentration (CAC) in the range of 0.01-0.14 g/L. The CAC of copolymers obviously depended on the hydrophobic block content in the copolymers (the value decreased with the increase of the pPhe block content). The cationic copolymers have the ability to form multi-interaction complex (MIC) with bovine serum albumin (BSA) and plasmid DNA through multi-interaction (electrostatic and hydrophobic interaction). The physicochemical characterization of the complex was carried out by the measurement of zeta potential and particle size. Their zeta-potentials were positive (approximately +10 mV) and their sizes decreased with increasing pPhe contents in the copolymers (PPF/BSA wt% ratio = 2). The complex showed good stability at high ionic strength. Therefore, mPEG-bPEI-pPhe block copolymer was considered as a potential material to enhance the stability of complex including biotherapuetic drugs.