• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1392-1396
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• 2005

Proteolytic digestion and CD measurement of wild-type and mutant cyclic AMP receptor proteins (CRPs) were performed either in the presence or absence of cyclic nucleotide. Results indicated that transition of a structural change to the hinge region by the binding of cAMP to the anti site was required for the binding of cAMP to the syn site near the hinge region and, although the occupancy of cAMP in the anti site increased the protein stability, CRP adopted more a stable conformation by the binding of cAMP to the syn site.

• 통합자연과학논문집
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• 제4권3호
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• pp.222-226
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• 2011

Cyclic AMP receptor protein(CRP) is involved in the activation of many genes corresponding to catabolite enzymes in Escherichia coli. In this study, mutant CRP(S128A) was used to elucidate the effect of Ser 128 on the cAMP-induced structural change. Based on the protease digestion and thermal analysis, serine 128 in CRP affects the cAMP binding capability and then structural change of CRP protein. In addition, CD spectra in near UV region revealed that S128A CRP retained the sensitive conformation to thermal effect relative to that of wild-type CRP, in spite of identical Tm values in the absence of cAMP.

• BMB Reports
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• 제45권12호
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• pp.693-699
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• 2012

Together with protein tyrosine kinases (PTKs), protein tyrosine phosphatases (PTPs) serve as hallmarks in cellular signal transduction by controlling the reversible phosphorylation of their substrates. The human genome is estimated to encode more than 100 PTPs, which can be divided into eleven sub-groups according to their structural and functional characteristics. All the crystal structures of catalytic domains of sub-groups have been elucidated, enabling us to understand their precise catalytic mechanism and to compare their structures across all sub-groups. In this review, I describe the structure and mechanism of catalytic domains of PTPs in the structural context.

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2002년도 International Symposium on Magnetic Resonance
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• pp.76-76
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• 2002

• BMB Reports
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• 제34권1호
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• pp.73-79
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• 2001

Transcriptional activation domains are known to be inherently "unstructured" with no tertiary structure. A recent NMR study, however, has shown that the transactivation domain in human p53 is populated with an amphipathic helix and two nascent turns. This suggests that the presence of such local secondary structures within the overall "unstructured" structural framework is a general feature of acidic transactivation domains. These pre-existing local structures in p53, formed selectively by positional conserved hydrophobic residues that are known to be critical for transcriptional activity, thus appear to constitute the specific structural motifs that regulate recognition of the p53 transactivation domain by target proteins. Here, we report the results of a NMR structural comparison between the native human p53 transactivation domain and an inactive mutant (22L,23W$\rightarrow$22R,23S). Results show that the mutant has an identical overall structural topology as the native protein, to the extent that the amphipathic helix formed by the residues 18T 26L within the native p53 transactivating domain is preserved in the double mutant. Therefore, the lack of transcriptional activity in the double mutant should be ascribed to the disruption of the essential hydrophobic contacts between the p53 transactivation domain and target proteins due to the (22L,23W$\rightarrow$22R,23S) mutation.

• 생명과학회지
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• 제14권5호
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• pp.752-760
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• 2004

Nitrogenase 촉매에서 Fe-단백질을 포함하는 [4Fe-4S] 클라스터의 기능은 기질의 결합과 환원 자리를 포함하는 MoFe-단백질로 핵산 의존 전자 주개로 작용하는 것이다. 이러한 방법의 Fe-단백질의 기능은 Mofe-단백질과 상호작용을 위해 적합한 구조를 갖추며 전자 전달을 위한 추진력을 제공하기 위해 산화 환원 퍼텐셜을 변화시키는 능력에 의존한다. Nitrogenase Fe-단백질에 MgADP가 결합한 (혹은 떨어진) 구조적 정보는 핵산 결합 자리로부터 MoFe-단백질과의 결합력을 조절하기 위한 장거리 상호작용 메커니즘을 제시한다. 스위치 I과 II의 두 가지 경로가 뉴클레오티드의 신호전달 메커니즘을 담당한다. MgADP가 결합된 Fe-단백질의 구조는 Fe 단백질이 핵산과 결합할 때 관찰되는 [4Fe-4S] 클라스터의 생물리학적 특성 변화의 기초를 제공한다. 스위치, I과 II의 핵산 의존 신호전달 경로에서 특정 아미노산이 치환된 nitrogenase Fe-단백질의 구조들이 X-선 회절법에 의해서 결정되었다. 이들 경로는 아미노산 치환 연구, 구조 분석, 유사한 핵산 의존 신호전달 경로에 이용된 다른 단백질 등에 의해서도 분석되었다. 이들 경로가 거대분자 착물 형성과 분자간 전자 전달을 위한 MgADP 결합과 가수분해의 신호전달 경로로의 타당성이 조사되었다. 이러한 결과는 nitrogenase Fe 단백질과 MoFe-단백질 착물에서 Fe-단백질의 변이와 상호작용의 생물리학적 및 생화학적 특성을 위한 기초적 자료를 제공할 것이다.

• 생명과학회지
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• 제11권1호
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• pp.43-47
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• 2001

A mutant tryptophan synthase $\alpha$-subunit, where Pro28 was replaced with Leu, tends to be expressed in recombinant E. coli. CD and fluorescence spectra of this protein indicate some changes in secondary and tertiary structure. Wild type protein was more or less affected by {TEX}$Ca^{2+}${/TEX} ion in regards of the fluorescent properties of its native, unfolded and intermediate forms, but the mutant protein was not at all. The dramatic structural changes may be related to the aggregation of this mutant protein.

• 전기전자학회논문지
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• 제13권3호
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• pp.18-23
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• 2009

FEATURE는 단백질 내에서 특정 기능이나 구조를 가지고 있는 site의 미세환경분포를 이용하여 다른 단백질 내에서 이와 유사한 미세환경을 가지고 있는 부분을 찾아 그 분분이 site일 확률을 수치적으로 제시해 줌으로써 사용자로 하여금 site의 존재 유무와 그 위치를 판단하는데 기준을 제공해주는 유용한 툴이다. 하지만 기존의 FEATURE에서 사용된 데이터 이외의 새로운 단백질 구조 데이터를 FEATURE에 적용하기 위해서는 FEATURE 내부의 module을 입력 데이터 구조에 맞게 수정해야 한다. 그러나 FEATURE 내부의 module 구조를 수정하는 방식이 직관적이지 않기 때문에 많은 연구자들이 FEATURE를 원활하게 사용하지 못하였다. 따라서 본 논문에서는 FEATURE의 내부 구조를 분석하고 FEATURE를 새로운 단백질 데이터에 적용하기 위한 방법을 제시한다.

• 생명과학회지
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• 제9권5호
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• pp.497-503
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• 1999

Change on the structural carbohydrate(several fiberous components) was determined by vegetables(crown daisy and butterbur)-cultivated in Ulsan, Kyungnam, Korea-as its stage of maturity developed. Samples were separated into leaf and stem, which were dried at 7$0^{\circ}C$ for 24hr, and ground to pass a 1mm screen. They were subjected to moisture, crude protein, crude fat and several dietary fiber-DF(dietary fiber, include unavaible components), NDF(neutral detergent fiber), ADF(acid detergent fiber), lignin, hemicellulose, cellulose and protein corrected NDF(c-NDF), IDF(indigestible fiber, include lignin, hemicellulose and cellulose). In general, structural carbohytrate(several dietary fiber) of vegetable was affected by the growth stage. In case of crown daisy and butterbur, dietary fiber in leaf was higher than DF in stem.

• 대한의생명과학회지
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• 제27권4호
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• pp.231-238
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• 2021

Several structural proteins present in keratinocytes of the skin are known to play an important role in the formation of epidermal tissue and barrier function, and the absence of structural proteins in keratinocytes causes various skin diseases. In this study, 42 types of tetrapeptides derived from the sequence of Loricrin, a kind of terminally differentiating structural protein, were synthesized, and skin anti-aging properties were measured by measuring the elastase inhibition, proliferation of skin cells. The anti-aging efficacy was verified and, based on this, it succeeded in selecting one of the most excellent peptides. It is expected that the selected tetrapeptide can be used as a raw material for various cosmetics and quasi-drugs based on anti-aging and skin cell proliferation effects.