• 미생물학회지
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• 제13권2호
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• pp.71-80
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• 1975

The neurotoxin of Clostridium botulinum type B was purified from a liquid culture. The purification steps consist of ammonium sulfate precipitation of whole culture, treatment of Polymin P(0.15%, v/v), gel filtration on Sephadex G-100 at pH5.6 and DEAE-Sephadex charomatography at pH8.0. The procedure recovered 17% of the toxin assayed in the starting culture. The toxin was homogeneous by sodium dodecyl sulfate(SDS)-polyacrylamide gel electrophoresis and had a molecular weight of 163,000. Subunits of 106,000 and 56,000 molecular weight were found when purified toxin was treated with a disulfide-reducing agent and electro phoresed on SDS-polyacrylamide gels.

• BMB Reports
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• 제31권3호
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• pp.227-232
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• 1998

The leukocyte NADPH oxidase of neutrophils is a membrane-bound enzyme that catalyzes the production of $O_2^-$ from oxygen using NADPH as an electron donor. Dormant in resting neutrophils, the enzyme acquires catalytic activity when the cells are exposed to appropriate stimuli. During activation, the cytosolic oxidase components $p47^{phox}$ and $p67^{phox}$ migrate to the plasma membrane, where they associate with cytochrome $b_{558}$, a membrane-bound flavohemoprotein, to assemble the active oxidase. The oxidase can be activated in a cell-free system; the activating agent usually employed is an anionic amphiphile such as sodium dodecyl sulfate (SDS). Because $p47^{phox}$ can translocate by itself during activation, the conformational change in $p47^{phox}$ may be responsible for the activation of NADPH oxidase. We show here that the treatment of $p47^{phox}$ with SDS leads to an increase in the reactivity of the sutbydryl group of cysteines toward N-ethylmaleimide, indicating that the conformational change occurs when $p47^{phox}$ is exposed to SDS. We propose that this change in conformation results in the appearance of a binding site through which $p47^{phox}$ interacts with cytochrome $b_{558}$during the activation process.

• 미생물학회지
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• 제24권2호
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• pp.106-112
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• 1986

자연계에서 분리한 Pseudomonas에서 크기가 매우 큰 plasmid (약 180 megadaltons:를 분리하였다. 이 plasmid는 기존의 plasmid 검출방법보다 더 온화한 조건에서 분리되었다. Alkalin., sodium dodecyl sulfate (pH 12. 45)를 사용하여 chromosomal DNA를 변성시킨 뒤 $55^{\circ}C$로 열처리 하여 covalently closed circular DNA 의 손실을 최대한으로 방지하였고, polyethylene glycol을 최종농도 10%로 첨가하여 plasmid DNA를 선택적으로 농축하였다. 한편, 이 plasmid는 mitomycin C를 처리하여 얻은 cured sitrains에서는 나타나지 않아 salicylate를 분해하는 새로운 plasmid로 확인되었다.

• Applied Biological Chemistry
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• 제37권4호
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• pp.243-247
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• 1994

한국산 대추로부터 조직의 연화에 작용하는 endo-polygalacturonase를 gel filtration과 이온교환크로마토그라피에 의하여 단일 단백질로 정제할 수 있었고, 수율은 약 6% 정도였다. 정제된 이 효소는 sodium dodecyl sulfate-polyacrylamide gel electrophoresis에 의하여 분자량이 약 19,000정도의 monomer로 확인되었고, 결정구조는 육각판상 모양을 나타내었다.

• 전기화학회지
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• 제13권3호
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• pp.163-168
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• 2010

본 연구에서는 양극 산화를 통해 얻어지는 다공성 니오븀 산화물 제조에 양이온 계면활성제인 Cetyl Trimethyl Ammonium Bromide (CTAB)와 음이온 계면활성제인 Sodium Dodecyl Sulfate (SDS)의 영향을 비교 관찰하였다. SDS가 전해질에 첨가되어 제조된 다공성 니오븀 산화 막은 표면에 장시간 용출이 발생하지 않았고, 계면활성제가 첨가되지 않고 제조된 다공성 니오븀 산화막의 두께와 비교 하였을 때 두께가 두 배 이상 증가된 값을 얻을 수 있었다. 하지만 CTAB가 전해질에 첨가되어 제조된 다공성 니오븀 산화물의 표면에는 용출이 일어났다. 이러한 차이점을 양성으로 대전된 니오븀산화물과 음이온/또는 양이온 계면활성제 사이의 상호작용에 근거하여 설명하였다.

• 한국동물학회지
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• 제33권1호
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• pp.119-125
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• 1990

Trypsin을 비롯한 여러 serine protease를 저해하는 단백질을 계골격근으로부터 여러 chromatography 방법을 이용하여 순수하게 분리하였다. 이 저해제의 분자량은 젤 여과법을 이용하여 측정한 결과 66,000 달톤이었으며 sodium dodecyl sulfate 존지하에서 전기영동하였을 때 66,000과 64,000 달톤의 두 단백질로서 나타났다. 이 중 64,000 달톤의 단백질은 순수분리과정 혹은 생체 내에서 일어난 부분 절제현상에 기인한 66,000 달톤 단백질의 부산물인 것으로 사료된다. 이 저해제는 약 7.4의 등전점을 가진 당 단백질임을 알 수 있었으며, 다량의 cysteine잔기를 포함하고 있다.

• 분석과학
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• 제13권1호
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• pp.22-26
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• 2000

2-Hydroxybenzaldehyde-5-nitro-pyridylhydrazone (2HB-5NPH)를 합성하여 계면활성제 하에서 바나듐 이온(IV)의 분광학적 정량에 응용하였다. pH, 용매효과, 리간드 농도와 계면활성제의 최적조건을 구하였다. 이 과정을 혼합 시료와 실제 시료 중의 바나듐(IV) 정량에 적용하여 만족한 결과를 얻었다(회수율 ${\geq}$ 97% ; $0{\sim}1.5{\mu}g/mL$ 농도 범위에서 상대 표준 편차 ${\leq}$ 3.0% ; 용액중에서 검출 한계 $0.02{\mu}g/mL$).

• Bulletin of the Korean Chemical Society
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• 제5권3호
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• pp.121-126
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• 1984

The charge transfer complex formations between indole derivatives and methylviologen were investigated spectroscopically. In aqueous solutions near room temperature, the order of complex stability was tryptamine < tryptophan < indole < indole acetate, which is the reverse order of the magnitude of molar absorptivities. This was interpreted as involvement of contact charge transfer. The decrease of enthalpy of complex formation (-${\Delta}$H) was highest in tryptamine, and lowest in indole acetate. ${\Delta}$H and entropy of complex formation (${Delta}$S) varied nearly in a linear fashion with isokinetic temperature $242^{\circ}$K. These results were attributed to the hydration-dehydration properties of the side chains in indole derivatives. Except indole acetate, the complex formations were greatly enhanced by the addition of sodium dodecyl sulfate(SDS). However, the direct relationship between the enhanced complex formation and SDS micelle formation was not found. The enhanced charge transfer interaction inSDS solutions was attributed to the increased ${\Delta}$S by interaction between methylviologen and SDS in premicellar level. The order of complex stability in SDS solutions was indole acetate < tryptophan < trypamine < indole, which reflects the hydrophobicity of indole derivatives as well as electrostatic interaction between indole derivatives and methylviologen associated with SDS.

• Bulletin of the Korean Chemical Society
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• 제10권5호
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• pp.437-442
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• 1989

The cmc's of sodium dodecyl sulfate (SDS)/Triton X-100 surfactant mixtures were determined by surface tension measurement at various surfactant compositions. The cmc values were lower than those predicted from ideal mixture. The regular solution theory was applied to calculate the interaction parameter, micellar composition, and the activity coefficients of surfactants in the mixed micelle. The interaction parameter (${\beta}$) was - 2.1. The nonideality arised largely from decreased activity of SDS in the mixed micelle. The mean aggregation numbers (${\bar{n}}$) and micropolarity of hydrocarbon region of the mixed micelles were determined by luminescence probe techniques. The total aggregation number (${\bar{n}}_{SDS}+{\bar{n}}_{TX}$) in mixed micelles showed little dependency on the composition of the micelle. The apparent dielectric constant of the hydrocarbon region of the micelle vs micellar composition plot showed positive deviation from linearity. Emission and emission quenching of excited tris(2,2'-bipyridine)ruthenium(Ⅱ) cation, $(Ru(bpy)_3^{2+})$, by methylviologen ($MV^{2+}$) were also investigated in the mixed micellar solutions. The quenching rate was lowest when the mole fraction of SDS in the surfactant mixtures (${\alpha}_{SDS}$) is about 0.25 and highest at ${\alpha}_{SDS}$ = 0.85. This was explained in terms of combined effects of binding of the cations with the micelle and mobility of the bound cations on the surface of the micelles.

• Elastomers and Composites
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• 제35권3호
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• pp.188-195
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• 2000

Host Polymer인 Poly(acrylonitrile-co-butadiene) (NBR)과 전도성 고분자인 Polypyrrole (PPY)과의 복합체를 유화 중합법으로 제조하였다. 여러 가지의 유화제 중에서 dodecyl sodium sulfate (DSS)를 사용하여 중합하였을 때 복합체의 전기전도도가 가장 높게 나타났다. 복합체 필름은 압축성형법으로 제조되었으며 복합체의 전기전도도는 전도성고분자의 함량과 온도에 따라 4단자법으로 측정되었다. 제조된 복합체의 전기전도도는 PPY 함량이 25wt%일 때 1.17S/cm까지 증가되었으며 percolation threshold는 PPY의 함량 l5wt% 근처에서 나타났다.