• Bulletin of the Korean Chemical Society
• /
• 제33권11호
• /
• pp.3681-3685
• /
• 2012

We developed a simple and effective method for the SERS-based detection of protein-small molecule complexes and label-free proteins using avidin-induced silver aggregation. Upon excitation with light of the appropriate wavelength (633 and 532 nm), the aggregated silver nanoparticles generate a strong electric field that couples with the resonance of the molecules (atto610 and cytochrome c), increasing the characteristic signals of these molecules and resulting in sensitive detection. The detection limit of biotin with the proposed method is as low as 48 ng/mL. The most important aspect of this method is the induction of silver aggregation by a protein (avidin), which makes the silver more biocompatible. This technique is very useful for the detection of protein-small molecule complexes.

• Journal of Gastric Cancer
• /
• 제12권3호
• /
• pp.140-148
• /
• 2012

Purpose: Among cell adhesion molecules, serum levels of intercellular adhesion molecule-1 and E-selectin are known to be correlated with the metastatic potential of gastric cancer. In the present study, the authors investigated the expression of intercellular adhesion molecule-1 and E-selectin in gastric cancer tissues and cultured gastric cancer cells, and examined their clinical value in gastric cancer. Materials and Methods: The protein was extracted from gastric cancer tissues and cultured gastric cancer cells (MKN-28 and Kato-III) and the expression of intercellular adhesion molecule-1 and E-selectin was examined by western blotting. The clinical significance of intercellular adhesion molecule-1 and E-selectin was explored, using immunohistochemical staining of specimens from 157 gastric cancer patients. Results: In western blot analysis, the expressions of intercellular adhesion molecule-1 in gastric cancer tissues and cultured gastric cancer cells were increased, however, E-selectin in gastric cancer tissues and cells were not increased. Among 157 gastric cancer patients, 79 patients (50%) were intercellular adhesion molecule-1 positive and had larger tumor size, an increased depth of tumor invasion, lymph node metastasis and perineural invasion. The intercellular adhesion molecule-1 positive group showed a higher incidence of tumor recurrence (40.5%), and a poorer 3-year survival than the negative group (54.9 vs. 85.9%, respectively). Conclusions: Intercellular adhesion molecule-1 is overexpressed in gastric cancer tissues and cultured gastric cancer cells, whereas E-selectin is not overexpressed. Increased expression of intercellular adhesion molecule-1 in gastric cancer could be related to the aggressive nature of the tumor, and has a poor prognostic effect on gastric cancer.

• 한국발생생물학회지:발생과생식
• /
• 제12권3호
• /
• pp.297-303
• /
• 2008

본 논문은 인공적인 단백질인 MCL-1ES BH3M에 관한 것으로 MCL-1ES BH3M를 과발현시 세포사멸을 유도한다. MCL-1L을 주형으로 재조합 PCR을 통해서 MCL-1ES BH3M를 클로닝하였다. 새롭게 클로닝한 단백질인 MCL-1ES BH3M 단백질은 안정성을 유지하기 위해서 PEST 도메인이 제거되어 있으며, 다른 BCL-2 패밀리 단백질과의 결합을 조절하기 위해서 BH3도메인의 Leu-Arg-Arg-Val-Gly-Asp-Gly 서열을 7개의 Ala 잔기로 인위적으로 돌연변이를 유도하였다. MCL-1ES BH3M를 293T 세포에서 과발현할 경우 세포사멸을 유도하였고, 항-세포사멸 단백질인 MCL-1L을 같이 과발현하더라도 세포사멸을 유도하였다. 또한, 과발현시 Caspase 9과 3를 활성화하였으며 면역염색법을 통해서 MCL-1ES BH3M 과발현시 미토콘드리아에 MCL-1ES BH3M 단백질이 부분적으로 위치하는 것을 확인하였다. 이상의 결과로 MCL-1ES BH3M는 Caspase 9과 3의 활성을 통해서 세포사멸을 유도한다. 결론적으로 본 연구는 세포사멸을 유도하는 새로운 molecule을 클로닝하였고, 이 molecule에 의한 세포사멸 기능을 확인하였다.

• Experimental and Molecular Medicine
• /
• 제50권11호
• /
• pp.12.1-12.12
• /
• 2018

Drugs targeting the epidermal growth factor receptor (EGFR), such as cetuximab and panitumumab, have been prescribed for metastatic colorectal cancer (CRC), but patients harboring KRAS mutations are insensitive to them and do not have an alternative drug to overcome the problem. The levels of ${\beta}$-catenin, EGFR, and RAS, especially mutant KRAS, are increased in CRC patient tissues due to mutations of adenomatous polyposis coli (APC), which occur in 90% of human CRCs. The increases in these proteins by APC loss synergistically promote tumorigenesis. Therefore, we tested KYA1797K, a recently identified small molecule that degrades both ${\beta}$-catenin and Ras via $GSK3{\beta}$ activation, and its capability to suppress the cetuximab resistance of KRAS-mutated CRC cells. KYA1797K suppressed the growth of tumor xenografts induced by CRC cells as well as tumor organoids derived from CRC patients having both APC and KRAS mutations. Lowering the levels of both ${\beta}$-catenin and RAS as well as EGFR via targeting the $Wnt/{\beta}$-catenin pathway is a therapeutic strategy for controlling CRC and other types of cancer with aberrantly activated the $Wnt/{\beta}$-catenin and EGFR-RAS pathways, including those with resistance to EGFR-targeting drugs attributed to KRAS mutations.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제33권5호
• /
• pp.445-454
• /
• 2007

Background: Phosphatidic acid(PA), an important second messenger, is involved in inflammation. Notably, cell-cell interactions via adhesion molecules playa central role in inflammation. This thesis show that PA induces expression of intercellular adhesion molecule-1(ICAM-1) on macrophages and describe the signaling pathways. Materials and methods: Macrophages were cultured in the presence of 10% FBS and assayed cell to cell adhesion using HUVEC. For the gene and protein analysis, RT-PCR, Western blot and flow cytometry were performed. In addition, overexpressed cell lines for dominant negative PKC-${\delta}$ mutant established and tested their effect on the promoter activity and expression of ICAM-1 protein by PA. Results: PA-activated macrophages significantly increased adhering to human umbilical vein endothelial cell and this adhesion was mediated by ICAM-1. Pretreatment with rottlerin(PKC-${\delta}$ inhibitor) or expression of a dominant negative PKC-${\delta}$ mutant, but not Go6976(classical PKC-${\alpha}$ inhibitor) and myristoylated PKC-${\xi}$ inhibitor, attenuated PA-induced ICAM-1 expression. The p38 mitogen-activated protein kinase(MAPK) inhibitor blocked PA-induced ICAM-1 expression in contrast, ERK upstream inhibitor didn't block ICAM-1. Conclusion: These data suggest that PA-induced ICAM-1 expression and cell-cell adhesion in macrophages requires PKC-${\delta}$ activation and that PKC-${\delta}$ activation is triggers to sequential activation of p38 MAPK.

• 한국컴퓨터그래픽스학회논문지
• /
• 제18권3호
• /
• pp.1-7
• /
• 2012

본 논문에서는 단백질 분자 간의 인터페이스를 계산하는 알고리즘을 제안한다. 분자가 반데르바스 (van der Waals) 반경을 갖는 구의 집합으로 표현될 때, 공간 상의 한 점 p로부터 분자까지의 거리는 p로부터 가장 가까운 구까지의 거리에 대응한다. 분자 인터페이스는 두 개의 분자에 대해 같은 거리에 있는 점들로 구성된다. 제안된 알고리즘은 공간을 복셀의 집합로 분할한뒤, 각 복셀을 지나는 구의 위치 정보를 저장하여 복셀맵 (voxel map)을 구성하였다. 복셀맵을 이용하여 한 점으로부터 분자까지의 거리를 계산하며, GPU (graphic processor unit)를 이용하여 병렬처리를 수행함으로써 효율적으로 인터페이스를 근사한다.

• Journal of Microbiology
• /
• 제37권1호
• /
• pp.21-26
• /
• 1999

Two novel calcium-binding proteins, named CAB-I and CAB-II, have been isolated from Streptomyces coelicolor. Purification of the calcium-binding proteins involved heat treatment, fractionation with ammonium sulfate, acid treatment, anion exchange and hydrophobic interaction column chromatography, FPLC gel filtration, and preparative isoelectric focusing. A chelex competitive assay and 45Ca autoradiography verified the calcium-binding ability of the proteins. The major band CAB-II has an apparent molecular weight of 26,000 determined by SDS-polyacrylamide gel electrophoresis and 340,000 determined by gel filtration. The isoelectric point of this molecule showed the acidic nature of the molecule. N-terminal amino acid sequence analysis shows homology to rat Ca2+/calmodulin-dependent protein kinase-II (CAB-II) and yeast phosphoprotein phosphatase (CAB-I).

• Mass Spectrometry Letters
• /
• 제13권4호
• /
• pp.115-124
• /
• 2022

Emerging evidence has shown that RNA-binding proteins (RBPs) dynamically regulate all aspects of RNA in cells and involve in major biological processes of RNA, including splicing, modification, transport, transcription and degradation. RBPs, as powerful and versatile regulatory molecule, are essential to maintain cellular homeostasis. Perturbation of RNA-protein interactions and aberration of RBPs function is associated with diverse diseases, such as cancer, autoimmune disease, and neurological disorders. Therefore, it is crucial to systematically investigate the RNA-binding proteome for understanding interactions of RNA with proteins. Thanks to the development of the mass spectrometry, a variety of proteome-wide methods have been explored to define comprehensively RNA-protein interactions in recent years and thereby contributed to speeding up the study of RNA biology. In this review, we systematically described these methods and summarized the advantages and disadvantages of each method.

• 진공이야기
• /
• 제2권1호
• /
• pp.4-9
• /
• 2015

A nanopore is a very small hole that can be used as single-molecule detector. The detection principle is based on monitoring the ionic current reduced by passage of a molecule through the nanopore as a voltage is applied across the nanopore. Here, we introduce biological nanopores and solid-state nanopores. Then, research and current trend about nanopore-based DNA biosensor and protein analysis are reviewed.

• Bulletin of the Korean Chemical Society
• /
• 제34권4호
• /
• pp.1286-1289
• /
• 2013