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Pichia pastoris에서 발현된 보리 알파아밀라제 Chimera 효소들의 특성
김태집,육정빈,최승호,장명운,Kim, Tae-Jip,Yuk, Jeong-Bin,Choi, Seung-Ho,Jang, Myoung-Uoon,Svensson, Birte 한국미생물학회 2010 미생물학회지 Vol.46 No.1
보리 맥아로부터 발견된 서로 다른 알파아밀라제 동질효소(AMY1, AMY2)는 80%에 달하는 높은 아미노산 서열의 상동성을 보이지만, 두 효소의 특성은 서로 달라 AMY1 효소는 낮은 농도의 칼슘 조건에서 최대 활성을 보이는 반면, AMY2 효소는 높은 칼슘이온 농도에서 높은 활성을 나타낸다. 또한 BASI (Barley ${\alpha}$-Amylase/Subtilisin Inhibitor) 단백질은 AMY2 효소만을 특이적으로 저해한다. 따라서 본 연구에서는 AMY1과 AMY2 효소의 유전자를 I, II, III의 세 부위로 나눈 후, 제한효소 처리에 의해 일부 부위를 상호 치환한 4종의 chimera 효소를 추가로 제조하고, Pichia pastoris 균주에서 대량 발현하였다. 이들 효소의 특성을 비교한 결과, 제 I 부위만이 상호치환된 AMY211 및 AMY122 효소의 경우, AMY1과 AMY2의 중간적 칼슘 의존성을 나타내었으며, BASI에 의한 저해효과는 AMY2의 제 I, II 부위를 포함하는 AMY221 효소에서만 관찰되었다. 따라서 보리 아밀라제의 제 I 부위 및 제 II 부위에 존재하는 아미노산 잔기들이 칼슘 의존성 및 BASI와의 결합에 중요한 역할을 담당하는 반면 제 III 부위는 이들 효소의 활성 차이에 영향을 미치지 않음을 확인하였다. Two different ${\alpha}$-amylase isozymes (AMY1 and AMY2) found in barley malt share up to 80% of amino acid sequence identity with each other, but their enzymatic properties differ remarkably. AMY1 shows the highest activity at low concentration of calcium ion, while AMY2 is highly active at high calcium concentration. Meanwhile, BASI (Barley ${\alpha}$-Amylase/Subtilisin Inhibitor) protein specifically inhibits only AMY2. In the present study, three separate regions in AMY genes (I, II, and III) were assigned on the basis of restriction enzyme sites and four kinds of chimeric amylases have been obtained by swapping a part of regions with each other. Each chimera gene was successfully over-expressed in Pichia pastoris. From the results of enzymatic characterization, both AMY211 and AMY122 showed the mixed or intermediate type of calcium-dependent activity between AMY1 and 2. Meanwhile, only AMY221 chimera could be significantly inhibited by BASI protein. As a result, it can be proposed that some amino acid residues in the region I and II, except region III, of barley ${\alpha}$-amylases play very important roles in calcium-dependency and interaction with BASI.
Kwon, Jung-Hoon,Lee, Dong-Hun,Jeong, Jei-Hyun,Yuk, Seong-Su,Erdene-Ochir, Tseren-Ochir,Noh, Jin-Yong,Hong, Woo-Tack,Jeong, Sol,Gwon, Gyeong-Bin,Lee, Sang-Won,Choi, In-Soo,Song, Chang-Seon Wildlife Disease Association 2017 Journal of wildlife diseases Vol.53 No.3
<P>Asian-lineage H5 highly pathogenic avian influenza viruses (HPAIV) have caused recurrent outbreaks in poultry and wild birds. In January 2014, H5N8 HPAIV caused outbreaks in South Korea and subsequently spread to East Asia, Europe, and North America. We report the isolation of an H5N8 HPAIV strain from wild birds in Seoul, the most-developed city in South Korea. We analyzed the complete genome sequence of this isolate and estimated its origin using a phylogenetic analysis. The Seoul H5N8 isolate clustered phylogenetically with strains isolated from migratory wild birds but was distinct from Korean poultry isolates. This H5N8 virus was likely introduced into the urbanized city by migratory wild birds. Therefore, wild bird habitats in urbanized areas should be carefully monitored for HPAIV.</P>
Kwon, Jung-Hoon,Lee, Dong-Hun,Swayne, David E.,Noh, Jin-Yong,Yuk, Seong-Su,Erdene-Ochir, Tseren-Ochir,Hong, Woo-Tack,Jeong, Jei-Hyun,Jeong, Sol,Gwon, Gyeong-Bin,Song, Chang-Seon Centers for Disease Control and Prevention 2016 Emerging infectious diseases Vol.22 No.3
<P>Highly pathogenic avian influenza A(H5N8) viruses were isolated from migratory waterfowl in South Korea during fall 2014–winter 2015, a recurrence after initial introduction in winter 2014. These reappeared viruses were phylogenetically distinct from isolates circulating in poultry farms in South Korea.</P>
Reassortant Clade 2.3.4.4 Avian Influenza A(H5N6) Virus in a Wild Mandarin Duck, South Korea, 2016
Kwon, Jung-Hoon,Lee, Dong-Hun,Swayne, David E.,Noh, Jin-Yong,Yuk, Seong-Su,Erdene-Ochir, Tseren-Ochir,Hong, Woo-Tack,Jeong, Jei-Hyun,Jeong, Sol,Gwon, Gyeong-Bin,Lee, Seok,Song, Chang-Seon U.S. Department of Health and Human Services * Cen 2017 Emerging Infectious Diseases Vol.23 No.5
<P>A reassortant clade 2.3.4.4 avian influenza A(H5N6) virus was isolated from a fecal sample of a Mandarin duck (<I>Aix galericulata</I>) in South Korea during October 2016. This virus was genetically similar to H5N6 subtype virus isolates from China, Vietnam, Laos, and Hong Kong, including human isolates.</P>
Kwon, Jung-Hoon,Noh, Yun Kyung,Lee, Dong-Hun,Yuk, Seong-Su,Erdene-Ochir, Tseren-Ochir,Noh, Jin-Yong,Hong, Woo-Tack,Jeong, Jei-Hyun,Jeong, Sol,Gwon, Gyeong-Bin,Song, Chang-Seon,Nahm, Sang-Soep Elsevier 2017 Veterinary microbiology Vol.203 No.-
<P><B>Abstract</B></P> <P>Wild birds play a major role in the evolution, maintenance, and dissemination of highly pathogenic avian influenza viruses (HPAIV). Sub-clinical infection with HPAI in resident wild birds could be a source of dissemination of HPAIV and continuous outbreaks. In this study, the pathogenicity and infectivity of two strains of H5N8 clade 2.3.4.4 virus were evaluated in the Mandarin duck (<I>Aix galericulata</I>) and domestic pigeon (<I>Columba livia domestica</I>). None of the birds experimentally infected with H5N8 viruses showed clinical signs or mortality. The H5N8 viruses efficiently replicated in the virus-inoculated Mandarin ducks and transmitted to co-housed Mandarin ducks. Although relatively high levels of viral shedding were noted in pigeons, viral shedding was not detected in some of the pigeons and the shedding period was relatively short. Furthermore, the infection was not transmitted to co-housed pigeons. Immunohistochemical examination revealed the presence of HPAIV in multiple organs of the infected birds. Histopathological evaluation showed the presence of inflammatory responses primarily in HPAIV-positive organs. Our results indicate that Mandarin ducks and pigeons can be infected with H5N8 HPAIV without exhibiting clinical signs; thus, they may be potential healthy reservoirs of the H5N8 HPAIV.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mandarin ducks and pigeons can be infected with H5N8 HPAI viruses without exhibiting clinical signs. </LI> <LI> The titer of excreted virus was relatively high in a Mandarin duck and was detected in multiple organs. </LI> <LI> Mandarin ducks and pigeons may be potential healthy reservoirs of the H5N8 HPAI virus. </LI> </UL> </P>