• BMB Reports
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• 제34권2호
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• pp.95-101
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• 2001

Tissue transglutaminase (TGII, $G{\alpha}h$) belongs to a family of enzymes which catalyze post-translational modification of proteins by forming isopeptides via $Ca^{2+}$-dependent reaction. Although TGII-mediated formation of isopeptides has been implicated to play a role in a variety of cellular processes, the physiological function of TGII remains unclear. In addition to this Tease activity, TGII is a guanosine triphosphatase (GTPase) which binds and hydrolyzes GTP It is now well recognized that the GTPase action of TGII regulates a receptor-mediated transmembrane signaling, functioning as a signal transducer of the receptor. This TGII function signifies that TGII is a new class of GTP-binding regulatory protein (G-protein) that differs from "Classical" heterotrimeric G-proteins. Regulation of enzyme is an important biological process for maintaining cell integrity. This review summarizes the recent development in regulation of TGII that may help for the better understanding of this unique enzyme. Since activation and inactivation of GTPase of TGII are similar to the heterotrimeric G-proteins, the regulation of heterotrimeric G-protein in the transmembrane signaling is also discussed.

• 미생물학회지
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• 제31권2호
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• pp.175-178
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• 1993

Alkaline .alpha.-amylase expressed in the transformant, Baciollus subtills MB809, containing alkaline amylase gene cloned from alkalophilic Bacillus sp. AL-8, was purified through for step separation processes. The purified alkaline .alpha.-amylase had molecular weight of app[roximately 59, 000 daltons on SDS-PAGE and Sephaex G-100 gel filtration. Amino acid sequence of terminal portion of the enzyme was analyzed with pure amylase eluted form the SDS-PAGE gel. N-terminal amino acid sequence of .alpha.-amylase was determined by the Edman degradation method and resulted in $NH_{2}$-ser-thr-ala-pro-ser-(ile)-lys-ala-gly-thr-(ile)-leu. For C-terminal amino acid sequencing, purified .alpha.-amylase was digested with carboxypuptidase A and B, and reverse-phase HPLC gradient elution system resulted in -thr-trp-pro-lys-COOH.

• BMB Reports
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• 제37권1호
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• pp.53-58
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• 2004

With advances in determining the entire DNA sequence of the human genome, it is now critical to systematically identify the function of a number of genes in the human genome. These biological challenges, especially those in human diseases, should be addressed in human cells in which conventional (e.g. genetic) approaches have been extremely difficult to implement. To overcome this, several approaches have been initiated. This review will focus on the development of a novel 'chemical genetic/genomic approach' that uses small molecules to 'probe and identify' the function of genes in specific biological processes or pathways in human cells. Due to the close relationship of small molecules with drugs, these systematic and integrative studies will lead to the 'medicinal systems biology approach' which is critical to 'formulate and modulate' complex biological (disease) networks by small molecules (drugs) in human bio-systems.

• BMB Reports
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• 제51권7호
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• pp.317-318
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• 2018

Plants are unable to relocate themselves to a more favorable location and thus have to deal with developmental programs and environmental cues wherever they happen to be. It is yet largely unknown how plant cells coordinate cellular activities and architectures to accomplish developmental processes and respond to environmental changes. By identifying and establishing a new cellular model system, we have discovered that two neighboring cell types in the abscission zone (AZ) of Arabidopsis flowers coordinate their activities to ensure a precise "cut" through a highly restricted area of plant tissue to bring about organ separation. From this perspective, we further discuss the essence of cellular coordination in AZ, the key molecules controlling the organ separation, and relevant implications.

• 대한의용생체공학회:의공학회지
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• 제29권4호
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• pp.255-266
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• 2008

In tissue engineering, scaffolds play an important role in the growth of cells to 3-D organs or tissues. For the success of tissue engineering, they should be mimicked to meet the requirements of natural extracellular matrix (ECM) in the body, such as mechanical properties, adhesiveness, porosity, biodegradability, and growth factor release, etc. Contrary to other materials, polymeric materials are adequate to engineer scaffolds for tissue engineering because controlling the structure and the ratio of components and designing various shapes and size are possible. In this review, the importance, major characteristics, processes, and recent examples of polymeric scaffolds for tissue engineering applications are discussed.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8047-8052
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• 2016

Proteases are important molecules that are involved in many key physiological processes. Protease signaling pathways are strictly controlled, and disorders in protease activity can result in pathological changes such as cardiovascular and inflammatory diseases, cancer and neurological disorders. Many proteases have been associated with increasing tumor metastasis in various human cancers, suggesting important functional roles in the metastatic process because of their ability to degrade the extracellular matrix barrier. Proteases are also capable of cleaving non-extracellular matrix molecules. Inhibitors of proteases to some extent can reduce invasion and metastasis of cancer cells, and slow down cancer progression. In this review, we focus on the role of a few proteases and their inhibitors in tumors as a basis for cancer prognostication and therapy.

• Animal cells and systems
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• 제12권1호
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• pp.1-9
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• 2008

In the developing limb, chondrogenesis is an important prerequisite for the formation of cartilage whose template is required for bone formation. Chondrogenesis is a tightly regulated multi-step process, including mesenchymal cell recruitment/migration, prechondrogenic condensation of the mesenchymal cells, commitment to the chondrogenic lineage, and differentiation into chondrocytes. This process is controlled exquisitely by cellular interactions with the surrounding matrix and regulating factors that initiate or suppress cellular signaling pathways and transcription of specific genes in a temporal-spatial manner. Understanding the cellular and molecular mechanisms of chondrogenesis is important not only in the context of establishing basic principle of developmental biology but also in providing research direction toward preventive and/or regenerative medicine. Here, I will overview the current understanding of cellular and molecular mechanisms contributing to prechondrogenic condensation processes, the crucial steps for chondrogenesis, focusing on cell-cell and cell-matrix interactions.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.815-820
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• 2014

We applied the two-color resonant two-photon ionization and mass-analyzed threshold ionization techniques to record the vibronic and cation spectra of 2,4-difluorophenol. As supported by our theoretical calculations, only the cis form of 2,4-difluorophenol involves in the two-photon photoexcitation and pulsed field ionization processes. The band origin of the $S_1{\leftarrow}S_0$ electronic transition of cis-2,4-difluorophenol appears at 35 647 ${\pm}2cm^{-1}$ and the adiabatic ionization energy is determined to be 70 $030{\pm}5cm^{-1}$, respectively. Most of the observed active vibrations in the electronically excited $S_1$ and cationic ground $D_0$ states mainly involve in-plane ring deformation vibrations. Comparing these data of cis-2,4-difluorophenol with those of phenol, cis-2-fluorophenol, and 4-fluorophenol, we found that there is an additivity rule associated with the energy shift resulting from the additional fluorine substitution.

• BMB Reports
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• 제42권6호
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• pp.356-360
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• 2009

In the present study we have examined human-mouse homologous intronless disease and non-disease genes alongside their extent of sequence conservation, tissue expression, domain and gene ontology composition to get an idea regarding evolutionary and functional attributes. We show that selection has significantly discriminated between the two groups and the disease associated genes in particular exhibit lower $K_{a}$ and $K_{a}/K_{s}$ while $K_{s}$ although smaller is not significantly different. Our analyses suggest that majority of disease related intronless human genes have homology limited to eukaryotic genomes and their expression is localized. Also we observed that different classes of intronless disease related genes have experienced diverse selective pressures and are enriched for higher level functionality that is essentially needed for developmental processes in complex organisms. It is expected that these insights will enhance our understanding of the nature of these genes and also improve our ability to identify disease related intronless genes.

• 대한기계학회논문집
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• 제8권2호
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• pp.178-183
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• 1984

본 연구에서는 108개의 아르곤 입자가 Lennard-Jones의 포텐셜함수로 상호작 용하고 있는 고밀도 액체계에 높은 전단율울 작요시켜 외력에 의하여 물성의 변화가 일어나고 있는 비평형상태의 액체가 나타내는 현상을 분자동력학을 이용하여 미시적 인 관점에서 고찰하므로써, 높은 전단하중으로 인하여 윤활유 내부에서 전단응력이 발생하고, 이완되는 과정과 이로 인하여 점성이 저하하는등 비평형상태하의 물성변화 를 예측하는데 도움이 되고자 한다.