• BMB Reports
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• 제38권4호
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• pp.373-380
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• 2005

For measles viruses, fusion on the cell membrane is an important initial step in the entry into the infected cells. The recent research indicated that hemagglutinin firstly leads the conformational changes in the fusion protein then co-mediates the membrane fusion. In the work, we use the co-immunoprecipitation and pull-down techniques to identify the interactions among fusion protein, hemagglutinin and signaling lymphocyte activation molecule (SLAM), which reveal that the three proteins can form a functional complex to mediate the SLAM-dependent fusion. Moreover, under the confocal microscope, fusion protein and hemagglutinin protein can show the cocapping mediated by the SLAM. So fusion protein not only is involved in the fusion but also might directly interact with the SLAM to be a new fusion-trimer model, which might account for the infection mechanism of measles virus.

• Journal of Microbiology and Biotechnology
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• 제18권9호
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• pp.1492-1495
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• 2008

Successful control of Xanthomonas oryzae pv. oryzicola, the causal agent of bacterial leaf streak, requires a specific and reliable diagnostic tool. A pathovar-specific PCR assay was developed for the rapid and accurate detection ofthe plant pathogenic bacterium Xanthomonas oryzae pv. oryzicola in diseased plant. Based on differences in a membrane fusion protein gene of Xanthomonas oryzae pv. oryzicola and other microorganisms, which was generated from NCBI (http://www.ncbi.nlm.nih.gov/) and CMR (http://cmr.tigr.org/) BLAST searches, one pair of pathovar-specific primers, XOCMF/XOCMR, was synthesized. Primers XOCMF and XOCMR from a membrane fusion protein gene were used to amplity a 488-bp DNA fragment. The PCR product was only produced from 4 isolates of Xanthomonas oryzae pv. oryzicola among 37 isolates of other pathovars and species of Xanthomonas, Pectobacterium, Pseudomonas, Burkholderia, Escherichia coli, and Fusarium oxysporum f.sp. dianthi. The results suggested that the assay detected the pathogen more rapidly and accurately than standard isolation methods.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.32-32
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• 2003

In the neuron, SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) assembly plays a central role in driving membrane fusion, a required process for neurotransmitter release. In the cytoplasm, vesicular SNARE VAMP2 (vesicle-associated membrane protein 2) engages with two plasma membrane SNAREs syntaxin 1A and SNAP-25 (synaptosome-associated protein of 25 kDa) to form the core complex that bridges two membranes. While various factors regulate SNARE assembly, the membrane also plays the regulatory role by trapping VAMP2 in the membrane. The fluorescence and EPR analyses revealed that the insertion of seven C-terminal core-forming residues into the membrane controls complex formation of the entire core region, even though preceding 54 core-forming residues are fully exposed and freely moving. When two interfacial Trp residues in this region were replaced with hydrophilic serine residues, the mutation supported rapid complex formation.

• Journal of Microbiology and Biotechnology
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• 제24권4호
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• pp.568-576
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• 2014

TIM-1 (also known as KIM-1 and HAVcr-1) is a type I transmembrane glycoprotein member of the TIM family that may play important roles in innate and adaptive immune responses. The overexpression of proteins associated with membrane proteins is a major obstacle to overcome in studies of membrane protein structures and functions. In this study, we successfully coupled the overexpression of the TIM-1 protein with a C-terminal enhanced green fluorescent protein (GFP) tag in Escherichia coli. To the best of our knowledge, this report is the first to describe the overexpression of human TIM-1 in E. coli. The purified TIM-1-EGFP fusion protein recognized and bound directly to apoptotic cells and did not to bind to viable cells. Furthermore, we confirmed that the interactions of TIM-1-EGFP with apoptotic cells were blocked by TIM-1-Fc fusion proteins. This fusion protein represents a readily obtainable source of biologically active TIM-1 that may prove useful in future studies of human TIM-1.

• Applied Microscopy
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• 제13권1호
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• pp.31-40
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• 1983

Ultrathin sections of intact mycelia, released protoplast and fused protoplast of Micromonospora rosaria were observed by electron microscopy Intact mycelia showed a typical gram-positive bacterial cell wall structure and mesosomes. Released protoplasts had no cell wall components and fibrous nuclear region was distinguished from cytoplsmic region clearly. Protoplasts which treated with sucrose supplemented buffer were stable. But those treated with buffer without sucrose were extensively damaged, forming mom braneous vesicles. It was surmised that those vesicles originated from the damaged cytoplasmic membrane. High frequency of fusion was achieved by 50%(w/v). polyethylene-glycol 1,000 Fusion bodies in different stage of fusion were observed. Cell membrane barrier was stepwise relieved.

• 폴리머
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• 제32권4호
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• pp.328-333
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• 2008

삼투압을 이용한 약물전달시스템은 소화관내의 물이 다공성막을 통하여 시스템 내부로 침투하면 시스템 내부에 있던 삼투압물질과 섞여 삼투압을 발생시키고, 이 삼투압의 힘으로 시스템 내부에 있는 약물을 시스템 외부로 일정한 속도로 방출하는 제제기술이다. 이러한 삼투압을 이용하여 상용화된 대표적인 제품으로 니페디핀을 모델약물로 한 타블렛제형인 Procadia $XL^{(R)}$(Pfizer)과 $Adalat^{(R)}$(Bayer)가 널리 상용화되어 있다. 이번 연구에서는 타블렛 형태의 삼투압정을 유동층코팅 기술을 이용하여 삼투성펠렛으로 제조하였다. 삼투성펠렛은 수팽윤성 고분자와 삼투염을 포함한 시드층, 모델약물인 니페디핀을 포함하는 약물층 그리고 약물의 방출을 조절할 수 있는 다공성막으로 구성되어 있다. 본 연구에서는 다공성막으로 사용되는 초산셀룰로오스(CA)와 $Eudragit^{(R)}$ RS의 구성비와 코팅두께에 따른 약물방출 거동을 확인하였으며, 다공성막의 구성물질인 CA의 비가 증가할수록 또한 다공성막의 코팅두께가 증가할수록 같은 측정시간 때에 약물의 방출이 낮게 나타남을 확인하였다. 약물방출 전후의 펠렛의 형태를 확인하기 위하여 SEM을 측정하였다.

• Journal of Microbiology and Biotechnology
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• 제22권11호
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• pp.1575-1579
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• 2012

Paenibacillus polymyxa is known to be a plant-growth-promoting rhizobacterium. The present study describes a quantitative polymerase chain reaction (qPCR) assay for the specific detection and quantitation of P. polymyxa using a primer pair based on the sequence of a membrane-fusion protein for the amplification of a 268 bp DNA fragment. This study reports that the qPCR-based method is applicable for the rapid and sensitive detection of P. polymyxa and can be used as an alternative method for agricultural soil monitoring.

• Molecules and Cells
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• 제26권6호
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• pp.517-529
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• 2008

Porosomes are supramolecular, lipoprotein structures at the cell plasma membrane, where membrane-bound secretory vesicles transiently dock and fuse to release inravesicular contents to the outside during cell secretion. The mouth of the porosome opening to the outside, range in size from 150 nm in diameter in acinar cells of the exocrine pancreas, to 12 nm in neurons, which dilates during cell secretion, returning to its resting size following completion of the process. In the past decade, the composition of the porosome, its structure and dynamics at nm resolution and in real time, and its functional reconstitution into artificial lipid membrane, have all been elucidated. In this mini review, the discovery of the porosome, its structure, function, isolation, chemistry, and reconstitution into lipid membrane, the molecular mechanism of secretory vesicle swelling and fusion at the base of porosomes, and how this new information provides a paradigm shift in our understanding of cell secretion, is discussed.

• Journal of Microbiology
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• 제35권1호
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• pp.72-77
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• 1997

The baculovirus gp64 glycoprotein is a major component of the envelope protein of budded virus (BV). It has been shown that the gp64 glycoprotein plays an essential role in the infection process, especialy fusion between virus envelope and cellular endosomic membrane. Recently we reported optimal conditions required for gp64-mediated membrane fusion in pGP64 DNA transfected Spodoptera frugiperda (Sf9) cells (H. J. Kim and J. M. Yang, Jour, Microbiology, 34.7-14). In order to investigate the role of hydrophobicity within the fusion domain of the gp64 glycoprotein for membrane fusion, 13 mutants which have substitution mutation within hydrophobic region I were constructed by PCR-derived site-derected mutagenesis. Each mutated gp64 glycoproteins was transiently expressed by transfecting plasmid DNA into Spodoptera frugiperda (Sf9) cells. Oligomerization of the transisently expressed gp64 glycoproteins was a nalysed by running them on SDS-polyacrylamide gel electrophoresis under non-reducing condition followed by immunoblotting. All of the mutant gp64 glycoproteins expect cysteine-228 were able to form trimers. These results suggest that hydrophobic region I of the gp64 may not be responsible for the oligomerization of the gp64 glycoprotein.

• 폴리머
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• 제32권2호
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• pp.103-108
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• 2008

삼투정 펠렛은 경구를 통한 약물전달 시스템에 폭넓게 사용되고 있으며, 이러한 삼투정 펠렛은 수팽윤성 시드층과 모델약물인 니페디핀을 포함하는 약물층 그리고 약물의 방출을 조절하는 반투막 층으로 구성되어 있다. 이번 연구에서는 모델약물인 니페디핀을 포함한 삼투정 펠렛을 제조하고, 반투막층으로 사용되는 초산셀룰로오스(CA)와 Eudragit RS의 코팅두께에 따른 약물방출 거동과 알긴산 나트륨과 알긴산 나트륨의 가교가 삼투정 펠렛의 약물방출에 미치는 영향에 대하여 확인하고자 하였다. 모델약물인 니페디핀을 포함한 삼투정 펠렛의 제조는 유동층코팅기를 이용하여 제조하였으며, 비교적 높은 코팅 수율로 $1500{\sim}1700{\mu}m$ 내외의 펠렛이 제조됨을 SEM을 통하여 확인하였다. 이렇게 얻어진 펠렛의 반투막 층의 코팅두께에 따른 약물방출 거동을 보면 반투막의 코팅 두께가 증가할수록 약물의 방출이 지연됨을 확인하였다. 알긴산 나트륨을 반투막층 위에 코팅하였을 경우 인공위액(pH 1.2)에서는 약물방출이 거의 일어나지 않았으며, 인공장액(pH 6.8)으로 교체한 후 약물방출이 서서히 증가함을 알 수 있었다. 또한 알긴산 나트륨을 염화칼슘을 이용하여 가교시켰을 경우 약물의 방출이 급격히 감소함을 알 수 있었다. 이번 실험을 통하여 삼투정 펠렛의 약물방출은 반투막충의 코팅두께에 영향을 받으며, 알긴산 나트륨이 삼투정 펠렛의 약물방출에 영향을 끼침을 확인하였다.