• Applied Biological Chemistry
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• v.36 no.3
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• pp.172-177
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• 1993

To extract insoluble proteins from sesame meal residue by microorganism, the sesame meal residue was treated with crude enzyme solution of Bacillus sp. CW-1121. The foaming capacity of salt soluble protein was quite lower than that of water soluble protein and the foaming stability of salt soluble protein decreased abruptly in 10 min., while it sustained for 30 min in case of water soluble protein. Emulsion capacities of all the protein fractions showed minimum value near isoelectric point of protein and salt soluble protein had lower emulsion capacities than that of water soluble protein. The emulsion stability of the protein was relatively stable for 30 min at $80^{\circ}C$. Oil and water absorption capacities of salt soluble protein were higher than those of water soluble protein.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.164-170
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• 2005

To improve functional properties of food proteins, homologous or heterologous ${\beta}-casein$ and 11S globulin(glycinin) from animal and vegetable proteins, respectively, were bio-hybridized using transglutaminase(MTGase). Susceptibility was confirmed by SDS-PAGE, particle size analyzed, and emulsion stability tested using Reddy and Fogler method, To determine how bio-hybridized protein influences emulsion stability, protein bound on oil droplet was investigated using Scanning Electron Microscopy (SEM). formation of bio-hybridized protein band was detected among homologous and heterologous proteins, with heterologous protein forming weak band in oligomer form. Homologous ${\beta}-casein$ protein showed high emulsion stability, while homologous glycinin showed almost no stability. Stability of heterologous ${\beta}-casein$ and glycinin protein was higher than that of glycinin. SEM photographs showed even distribution of bio-hybridized proteins on oil droplet improved stability.

• Journal of the Korean Chemical Society
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• v.63 no.6
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• pp.427-434
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• 2019

The role of hydrophobic residues on protein folding reaction was studied by folding kinetics measurements in conjunction with protein engineering. The HubWA, which was derived from human ubiquitin by mutating the residues at 45 (Phe to Trp) and 26 (Val to Ala), was used as a mutational background. Fourteen hydrophobic residues were mutated to alanine. Among fourteen variants generated, only four variant proteins (V5A, I13A, V17A, and I36A) were suitable for folding study. The folding kinetics of these variants was measured by stopped-flow fluorescence spectroscopy. The folding kinetics of HubWA and V17A was observed to follow a three-state on-pathway mechanism. On the other hand, folding kinetics of V5A, I13A, and I36A was observed to follow a two-state mechanism. Based on these observations, transition of protein folding reaction from collision-diffusion mechanism to nucleation-condensation mechanism was discussed.

• Journal of the Korean Chemical Society
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• v.60 no.1
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• pp.82-87
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• 2016

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.259-260
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• 2000

넙치는 횟감으로 선호도가 높은 고급 어종으로 양식생산량이 꾸준히 증대되고 있는 주요양식 종이며, 단백질 요구량이 높은 육식성 어류이다. 배합사료의 단백질원으로서 가장 높은 비중을 차지하는 어분은 단백질 함량이 높고 필수아미노산 및 지방산이 골고루 갖춰진 양질의 단백질원이지만, 어획량의 변동으로 생산량이 불안정하기 때문에 영양소 조성, 소화율, 가격, 공급의 안정성 및 대상 어종의 기호성 등을 고려하여 어분을 대체할 수 있는 단백질원의 개발이 시급하다. 어분의 대체 단백질로 이용되는 원료 가운데 대두박은 아미노산 조성이 비교적 양호하고, 가격이 저렴할 뿐만 아니라 공급이 안정적이어서 여러 어종을 대상으로 활발히 연구되어 왔다. 따라서 경제적인 넙치 배합사료 개발의 일환으로 본 연구에서는 어분 대체 단백질원으로서 대두박의 이용성을 조사하였다. (중략)

• Applied Biological Chemistry
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• v.35 no.3
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• pp.152-156
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• 1992

A study was condoled to investigate the effects of phosphate salts $(Na_2HPO_4\;and\;K_2HPO_4)$ on the emulsion stability of soy protein isolate (SPI) in terms of the salts concentration and addition order. When phosphates were added before emulsification, emulsion stability (ES) of SPI was improved at the concentration of 10 mM, while ES was decreased by addition of phosphates after emulsification. At high phosphate concentrations, ES of SPI was decreased by the addition of phosphates, regardless of the addition order. ES of SPI at the isoelectric point (pH 4.5) or in the presence of $CaCl_2$ was greatly enhanced by the phosphates. In both cases, the overall ES profile was found to be nearly similar to the solubility profile of SPI, indicating the positive relationship between solutibility and emulsion stability of SPI.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.323-333
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• 1989

Plasmid DNA molecules containing strong promoter upstream from IS50L or IS50R, the two insertion sequences that flank Tn5, were constructed to amplify the synthesis of Tn5-encoded polypeptides. When proteins made by cells that contain these plasmids were analyzed on polyacrylamide gels, enhanced synthesis of IS50R polypeptides could be detected. Synthesis of this polypeptide apparently is initiated within the large open reading frame of this element. In addition, the stability of IS50L-and IS50R-encoded polypeptides was analyzed. It was found that IS50L polypeptides are relatively unstable in vivo. This instability could account for the observed inability of this element to promote transposition.

• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.160-165
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• 1997

The actomyosin and myosin of the squid at 3$0^{\circ}C$ showed the highest Vmax and the actomyosin and myosin of the clam at 35$^{\circ}C$ and HMM at $25^{\circ}C$ showed the highest Vmax the thermostability of myofibrillar proteins is changed greatly according to the difference of KCI concentration. The myofibrillar proteins of the clam showed a higher thermostability than the myofibrillar proteins of the squid. When 3% ethanol solution was added and heated myofibrillar proteins, denaturation was accelerated and it was shown that there was a difference between animals in the denaturation velocity.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.263-274
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• 2014

펩타이드 중합체의 이차 구조는 화학적, 생물학적 기능을 갖는 단백질 삼차 구조를 결정하는 중요한 구성요소이다. 이러한 단백질의 이차구조에 대한 정보는 치매, 광우병과 같은 단백질 응집관련 질병에서 응집유발 단백질의 형성과정 및 안정도와 밀접한 연관이 있다. 본 연구는 폴리알라닌을 모델 펩타이드로 선택하여, 이들의 가능한 7가지 이차구조들에 대한 구조적, 열역학적 특성을 계산화학방법을 통해 비교 분석하였다. 우선 기체상에서 7가지 구조들의 구조최적화를 통해 상대적 안정도를 비교하였고, 나아가 EDISON의 용매화 자유 에너지의 열역학적 계산방법을 통해 수용액상에서의 상대적인 안정도와 그 원인을 비교, 분석하였다. 특히, 기체상에서와 수용액상애서 폴리알라닌 이차구조들의 상대적 안정도가 바뀌는 원인에 대해, 폴리알라닌의 구조적 특징과 수소결합과의 상관관계를 통해 규명하였다. 본 연구에서 밝힌 단백질 이차 구조의 상대적 안정도 및 물과의 상관관계에 미치는 구조적, 열역학적 원인은 응집 유발 단백질에서 제시된 특정 이차 구조의 선택적 안정성에 대한 근거를 제시하며, 그 기작을 이해하는 중요한 단서를 제공한다.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.177-181
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• 2005

근원섬유 단백질에 카제인염을 첨가함으로써 유화안정성이나 보수력을 증진시킬 수 있으나 가제인염은 열에 안정성이 떨어지는 단점을 가지고 있다. TGase가 이러한 카제인염의 단점을 보완해주는지 알아보기 위해 열량분석기와 전기영동을 이용하여 단백질의 변화를 측정하였다. 열량분석기의 경우 근원섬유 단백질과 카제인 염 단백질의 상호교차결합을 TGase의 첨가유무에 따라 실시하였으며 그 결과 TGase의 첨가는 각 단백질 열량변화가 나타나는 온도를 변화시켰으며 배양시간을 증가할수록 각 단백질별 열량변화의 차이를 보였고 peak의 크기에도 차이를 보였다. 또한 전기영동의 경우 MFP, SC, MFP:SC의 1:1 혼합액을 각각을 TGase 첨가한 것과 하지 않은 것을 비교한 결과, TGase의 첨가는 고분자 polymer를 만들어줌으로써 두 단백질간의 상호작용에 촉매제로써 작용한다는 것을 확인하였다.