• 한국자기공명학회논문지
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• 제2권2호
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• pp.85-105
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• 1998

Prions cause neurodegenerative diseases in animals and humans. The scrapie prion protein (PrPSc) is the major-possibly only-component of the infectious prion and is generated from the cellular isoform (PrPC) by a conformational change. Limited proteolysis of PrPSc produces an polypeptide comprised primarily of residues 90 to 231, which retains infectivity. The three-dimensional structure of rPrP(90-231), a recombinant protein resembling PrPC with the Syrian hamster (SHa) sequence, was solved using multidimensional NMR. Low-resolution structures of rPrP(90-231), synthetic peptides up to 56 residues, a longer (29-231, full-length) protein with SHa sequence, and a short here further structure refinement of rPrP(90-231) and dynamic features of the protein. Consideration of these features in the context of published data suggests regions of conformational heterogeneity, structural elements involved in the PrPC\longrightarrowPrPSc transformation, and possible structural features related to a species barrier to transmission of prion diseases.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6305-6310
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• 2012

Objectives: This study aimed to demonstrate the tyrosine phosphorylation motif (TPM) and 3' region structure of the Helicobacter pylori CagA gene as well as its SHP-2 binding activity in AGS cells and relation to gastric carcinogenesis. Methods: Sixteen clinical isolate H. pylori strains from eight duodenal ulcer and eight gastric adenocarcinoma patients were studied for CagA repeat sequence EPIYA motifs, C-terminal structure, and western blot analysis of CagA protein expression, translocation, and SHP-2 binding in AGS cells. Results: Except for strain 547, all strains from the gastric adenocarcinoma patients were positive for CagA by PCR and had three EPIYA copy motifs. Western blotting showed that all strains were positive for CagA protein expression (100%), CagA protein translocation (100%), and SHP-2 binding (100%). CagA protein expression was significantly higher in the gastric adenocarcinoma patients than in the duodenal ulcer patients (P=0.0023). CagA protein translocation and SHP-2 binding in the gastric adenocarcinoma patients were higher than those in the duodenal ulcer patients, but no significant differences were found between the two groups (P=0.59, P=0.21, respectively). Conclusions: The TPMs and 3' region structures of the H. pylori CagA gene in the duodenal ulcer and gastric adenocarcinoma patients have no significant differences.

• 대한수의학회지
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• 제29권4호
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• pp.541-548
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• 1989

오제스키병 바이러스를 배양세포에다 감염시켜, 냉동 및 araldite포매 초박절편에서 protein A-gold labeling을 통해 바이러스항원 검출을 시도하였다. 오제스키병 바이러스항원은 10nm gold probes로 표지되었으며, 전자밀도가 높은 gold 입자들은 바이러스의 nucleocapsid와 envelope에서 주로 관찰되었고, 초냉동박절표본에서의 immunogold labeling은 조직구조물들과 극히 미미한 비특이결합만을 보였다. 초냉동박절표본에서의 immunogold labeling은 오제스키병 바이러스항원을 검출하는데 있어 효과적이었으며, 이는 또한 여러가지 바이러스들과 속주세포들간의 상호작용에 관한 면역세포화학적 연구에 크게 이용될 수 있을 것으로 생각된다.

• Journal of Microbiology
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• 제39권4호
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• pp.293-299
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• 2001

The nucleocapsid(NP) protein of Newcastle disease virus (NDV) and its derivative (NP$\sub$cfus)containing the myc region and six histidine residues fused to its C-terminus were pcpressed aboundantly in Escherichia coli. The proteins were purified by sucrose gradient centrifugation. Both the NP and NP$\sub$cfus/ proteins self-assem- bled into ring-like particles stacked together to from nucleocapsid-like structure which are heterogeneous in length with a diameter of 20${\pm}$2 nm and central holow of 5${\pm}$1 nm. Only a very small amount of the monomers in the particles was linked by inter-molecular disulfide bonds. Fusion of the C-terminal end to 29 amino acids inclusive of the myc epitope and His tag did not impair ring assembly buy inhibited the formation of the long herringbone structures. Immunogold lableing of the particles with the anti-myc antibody showed that the C-terminus of the NP$\sub$cfus/ protein is exposed on the surface of these ring-like particles.

• 정보처리학회논문지D
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• 제10D권2호
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• pp.261-266
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• 2003

단백질은 아미노산의 선형 중합체(linear polymer)로서 생체의 조직을 구성하고 각종 생화학 반응을 조절하는 역할을 하는 가장 중요한 생체 분자에 속한다. 이러한 단백질의 특성과 기능은 해당 단백질을 구성하는 아미노산의 서열에 의해 결정되기 때문에, 주어진 단백질의 서열을 알아내는 것은 단백질 기능 연구의 출발점이다. 본 논문은 기존의 생화학적 단백질 서열 결정 방법의 단점을 극복할 수 있는 데이터 마이닝 기반 단백질 서열 예측 기법을 제안한다. 복수개의 단백질 절단효소(protease)를 적용함으로써, 서로 중첩된 단백질 조각을 얻어내고, 각 조각의 질량 정보와 단백질 데이타베이스를 이용하여 후보 서열을 식별한다. 얻어진 후보 서열의 조립을 통해 전체 서열을 결정하기 위한, 다중 분할 그래프(multi-partite graph) 구축 및 경로 탐색 기법을 제안한다. 아울러, 대표적인 단백질 서열 데이타베이스인 SWISS-PROT을 이용한 실험을 통해 제안한 방법의 성능을 평가한다.

• Bulletin of the Korean Chemical Society
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• 제33권6호
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• pp.2005-2011
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• 2012

Nopp140 is a highly phosphorylated protein that resides in the nucleolus of mammalian cell and is involved in the biogenesis of the nucleolus. It interacts with a variety of proteins related to the synthesis and assembly of the ribosome. It also can bind to a ubiquitous protein kinase CK2 that mediates cell growth and prevents apoptosis. We found that Nopp140 is an intrinsically unfolded protein (IUP) lacking stable secondary structures over its entire sequence of 709 residues. We discovered that mitoxantrone, an anticancer agent, was able to enhance the interaction between Nopp140 and CK2 and maintain suppressed activity of CK2. Surface plasma resonance studies on different domains of Nopp140 show that the C-terminal region of Nopp140 is responsible for binding with mitoxantrone. Our results present an interesting example where a small chemical compound binds to an intrinsically unfolded protein (IUP) and enhances protein-protein interactions.

• 한국축산식품학회지
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• 제43권2호
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• pp.305-318
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• 2023

This study investigated the protein digestibility of chicken breast and thigh in an in vitro digestion model to determine the better protein sources for the elderly in terms of bioavailability. For this purpose, the biochemical traits of raw muscles and the structural properties of myofibrillar proteins were monitored. The thigh had higher pH, 10% trichloroacetic acid-soluble α-amino groups, and protein carbonyl content than the breast (p<0.05). In the proximate composition, the thigh had higher crude fat and lower crude protein content than the breast (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrillar proteins showed noticeable differences in the band intensities of tropomyosin α-chain and myosin light chain-3 between the thigh and breast. The intrinsic tryptophan fluorescence intensity of myosin was lower in the thigh than in the breast (p<0.05). Moreover, circular dichroism spectroscopy of myosin revealed that the thigh had higher α-helical and lower β-sheet structures than the breast (p<0.05). The cooked muscles were then chopped and digested in the elderly digestion model. The thigh had more α-amino groups than the breast after both gastric and gastrointestinal digestion (p<0.05). SDS-PAGE analysis of the gastric digesta showed that more bands remained in the digesta of the breast than that of the thigh. The content of proteins less than 3 kDa in the gastrointestinal digesta was also higher in the thigh than in the breast (p<0.05). These results reveal that chicken thigh with higher in vitro protein digestibility is a more appropriate protein source for the elderly than chicken breast.

• 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.

• Journal of Microbiology and Biotechnology
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• 제17권8호
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• pp.1236-1241
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• 2007

Five fusion proteins between Z domains derived from Staphylococcal Protein A and Green Fluorescent Protein or Human Proinsulin were produced on the periplasm of Escherichia coli. The effects of the molecular weight and amino acid composition of the translocated peptide, culture medium composition, and growth phase of the bacterial culture were analyzed regarding the expression and periplasmic secretion of the recombinant proteins. It was found that secretion was not affected by the size of the translocated peptide (17-42 kDa) and that the highest periplasmic production values were obtained on the exponential phase of growth. Moreover, the highest periplasmic values were obtained in minimal medium, showing the relevance of the culture medium composition on secretion. In silico prediction analysis suggested that with respect to the five proteins used in this study, those that are prone to form ${\alpha}$-helix structures are more translocated to the periplasm.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1628-1628
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• 2001

Near infrared (NIR) spectroscopy is a powerful technique for non-destructive analysis that can be obtained in a wide range of environments. Recently, NIR measurements have been utilized as probe for quantitative analysis in agricultural, industrial, and medical sciences. In addition, it is also possible to make practical application on NIR for molecular structural analysis. In this work, Fourier transform near infrared (FT-NIR) measurements were carried out to utilize extensively in the relative amounts of different secondary structures were employed, such as Iysozyme, concanavalin A, silk fibroin and so on. Several broad NIR bands due to the protein absorption were observed between 4000 and $5000\;^{-1}$. In order to obtain more structural information from these featureless bands, second derivative and Fourier-self-deconvolution procedures were performed. Significant band separation was observed near the feature at $4610\;^{-1}$ ,. Particularly the peak intensity at $4525\;^{-1}$ shows a characteristic change with thermal denaturation of fibroin. The structural information can be also obtained by mid-IR and CD spectral. Correlation of NIR spectra with protein structure is discussed.