• Applied Microscopy
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• 제24권4호
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• pp.41-51
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• 1994

The topology of the enzyme has been investigated by biochemical studies including chemical labeling and cross linking. Thirteen subunits(polypeptides) of the cytochrome-c-oxidase have localistic characteristics of existing in the matrix side or cytoplasmic side in the mitochondria. In order to observe the distribution of the enzyme subunit on the mitochondria membrane, immunogold-labeling methods were employed. Antibody was obtained from the serum of immunized rabbit with enzyme subunit antigen which was obtained from cytochrome-c-oxidase of the beef heart muscle mitochondria. Beef heart muscle tissue as a tissue antigen was stained with immunized rabbit IgG and protein A gold complex. Electron microscopy has identified the existance of cytochrome-c-oxidase subunit $Mt_I,\;Mt_{II}\;and\;Mt_{III}$ on the membrane of cristae and outer chamber of mitochondria and the subunit $C_{IV}$ on the membrane of cristae and matrix of mitochondria. Particularly, the subunit $C_{IV}$ was also observed to exist in the sarcoplasm of muscle tissue.

• 대한약리학회지
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• 제32권3호
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• pp.347-355
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• 1996

흰쥐 뇌하수체 전엽배양세포에서 PKC나 cAMP에 의한 LH 분비와 $LH{\beta}$subunit mRNA 증가과정에서 세포외 $Ca^{++}$의 역할을 검증하기 위하여 phorbol ester와 forskolin에 의해 촉진된 LH 분비와 $LH{\beta}$ subunit mRNA 수준에 미치는 EGTA와 verapamil의 영향을 조사하였다. Forskolin에 의해 촉진된 LH 분비와 $LH{\beta}$ subunit mRNA 수준은 $Ca^{++}$ chelator인 EGTA나 $Ca^{++}$ 채널차단제인 verapamil의 처리로 세포외부로부터 $Ca^{++}$의 이동을 억제시켰을때 모두 감소하였다. PMA에 의해 유도된 LH 분비는 EGTA와 verapamil 처리에 의해 영향을 받지 않았으나 PMA에 의해 촉진된 $LH{\beta}$ subunit mRNA는 억제되었다. 따라서 본 연구에 의하면 PKC 활성화나 세포내 cAMP 농도 증가는 $LH{\beta}$ subunit mRNA 수준을 증가시키며 이러한 과정은 세포외 $Ca^{++}$ 의존적인 것으로 생각된다. 그러나 PKC 활성화나 cAMP 증가에 의한 세포외 $Ca^{++}$의 역할이 서로 다른 양상을 보인다. PKC 활성화에 의한 LH 분비는 세포외 $Ca^{++}$에 비의존적이나 cAMP에 의해 촉진된 LH 분비는 세포외 $Ca^{++}$ 유입의 영향을 받는 것으로 사료된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권2호
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• pp.163-168
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• 2002

We report for the first time the cDNA sequence encoding a ferritin subunit from the spiders Araneus ventricosus. The complete cDNA sequence of A. ventricosus ferritin subunit comprised 516 bp with 172 amino acid residues. The A. ventricosus ferritin subunit cDNA contained a conserved iron responsive element sequence in the 5 untranslated region. An alignment of the deduced protein sequence of the A. ventricosus ferritin subunit gene to that of other heavy chain ferritin molecules showed that A. ventricosus ferritin subunit is most similar to the great pond snail, Lymnaea stagnalis, ferritin with 70.2% of protein sequence identity.

• 한국초지조사료학회지
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• 제22권1호
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• pp.51-58
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• 2002

식물의 광합성에 관여하는 광계 I의 protein subunit들의 연구는 최근까지도 극히 미약한 실정이며, 각각의 subunit들의 특성 또한 일부만이 밝혀져 있다. 본 연구진은 배추의 cDNA library로부터 식물에만 존재하는 subunit 중의 하나인, PSI-H subunit을 암호화하는 유전자인 bpsaH를 분리하였다. 이 유전자는 총 633 bp의 염기로 구성되어 있으며, 염기서열로부터 추정되는 분자량은 약 15,400이었고 등전점은 9.91이었다. 배추 PSI-H subunit의 아미노산 서열을 다른 식물체 유래의 단백질들과 비교분석한 결과, 시금치의 PSI-H와 가장 높은 유사성 (79.3%)을 나타내었다. 또한 bpsaH의 조직 특이적 발현 양상을 조사한 결과, 광합성 조직인 잎에서는 강하게 발현된 반면 꽃봉우리에서는 약하게 발현되었으며, 비광합성 조직인 뿌리에서는 전혀 발현되지 않았다.

• 한국미생물·생명공학회지
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• 제36권4호
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• pp.314-319
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• 2008

Penicillin G amidase(PGA, benzylpenicillinamidohydrolase, EC 3.5.1.11)는 penicillin G를 phenylacetic acid(PAA)와 6-aminopenicillanic acid(6-APA)로 분해하는 효소이다. Escherichia coli(E. coli) ATCC 11105의 PGA는 24 kDa의 small subunit과 65 kDa의 large subunit으로 구성되어 있고, precursor polypeptide에서 signal peptide와 spacer peptide가 절단되어 활성을 가진 heterodimer가 형성된다. 본 연구에서는 E. coli ATCC 11105에서 PCR(polymerase chain reaction)을 통해 증폭한 pga gene을 expression vector에 넣어 pET-pga plasmid를 제작하였고, 이것을 E. coli BL21 (DE3) 균주에 형질 전환하여 PGA를 발현하고 그 활성을 분석하였다. E. coli BL21(DE3)/pET-pga 균주의 고밀도 배양액을 SDS-PAGE로 분석 했을 때, PGA의 precursor, large subunit, 그리고 small subunit으로 보이는 protein band가 나타났으며, PGA가 soluble form의 precursor로 발현되어 processing을 거쳐서 large subunit과 small subunit으로 절단되기도 하고, 일부는 insoluble form의 precursor로 발현되기도 하는 것으로 생각된다. 유가배양시 온도변화 전략을 사용하여 고농도 배양에서 발현을 유도하였다. 온도변화 전략은 $37^{\circ}C$에서 $28^{\circ}C$를 거쳐 $22^{\circ}C$로 3단계로 변화시켰다. 이러한 전략으로 PGA활성은 19.6 U/mL이며 균체량은 600 nm에서 흡광도가 62까지 도달하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제15권2호
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• pp.115-122
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• 2007

As the genome of B.mori is available in GenBank and the EST database of B.mori is expanding, identification of novel genes of B.mori is conceivable by data-mining techniques. We used the in silico cloning method to get the vacuolar-type $H^+-ATP$ synthetase (V-ATPase) c subunit (16 kDa proteolipid subunit) gene of B.mori and analysed with bioinformatics tools. The result was confirmed by RT-PCR and sequencing. The V-ATPase c subunit cDNA contains a 468 bp ORF. The ORF encoded a 155-residue protein that showed extensive homology with V-ATPase c subunits from other 15 species and contained four membrane-spanning helices. Tissue expression pattern analysis revealed that V-ATPase c expressed strongly in Malpighian tubules, not in fat body. This gene has been registered in GenBank under the accession number EU082222.

• Environmental Analysis Health and Toxicology
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• 제17권1호
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• pp.73-80
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• 2002

Pyruvate dehydrogenase phosphatase (PDP)와 kinase는 당대사시 해당과정에서의 대사 산물인 pyruvate를 acetyl CoA로 만들어 구연산 회로로 진입시켜 주는 효소인 pyruvate dehydrogenase complex (PDC)의 활성을 조절하는 중요한 효소이다. PDP의 catalytic subunit는 PDC의 dihydrolipoamide acetyltransferase (E2), PDP regulatory subunit (PDPr), 그리고 칼슘 결합 도메인 등으로 구성되어 있는 것으로 추측되어지고 있다. 본 연구에서는 그 구조와 기능과의 상관관계를 알아보기 위해 PDPc를 E. coli JM101에서 발현시켜 순수 정제 후 단백분해 효소를 이용한 제한적 가수분해 방법을 이용해 그 구조와 기능과의 상관관계에 대해 연구하고자 하였다 정제된 PDPc는 trypsin, chymotrypsin, Arg-C 그리고 elastase를 이용하여 3$0^{\circ}C$ 그리고 pH 7.0에서 제한적으로 분해시켰으며 각 분해산물의 아미노 말단의 아미노산 배열을 분석하였다. 그 결과 PDPc는 trypsin, chymotrypsin, elastase에 의해 N-terminal의 50 kD과 C-terminal의 10 kD의 두개의 분해산물을 만들었으며, Arg-C에 의해 50kD의 분해산물은 약 35kD와 15kD으로 더 가수분해가 되었다. 이러한 결과로 볼 때 PDPc는 앞에서 추측한데로 세개의 주요한 기능적 도메인으로 이루어져 있음을 알 수 있었다 또한 C-terminal의 10kD은 PDPc의 활성에는 영향을 주지 않는 것으로 밝혀졌으나 다른 도메인의 기능은 더 연구가 되어져야 할 것으로 생각된다.

• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.1031-1037
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• 2004

The interaction of chemoattractant receptors and $G{\alpha}_{16}$ was studied to provide the molecular basis to elucidate the interaction of chemoattractant receptors with $G{\alpha}_{16}$ subunit, thereby possibly contributing to finding novel targets for designing new type of G protein antagonists with anti-inflammatory effects. Experiments were performed to characterize the $G{\alpha}_{16}$ subunit domains responsible for efficient coupling to chemoattractant receptors. Thus, a series of chimeric $G{\alpha}_{11}G{\alpha}_{16}$ and $G{\alpha}_{16}G{\alpha}_{11}$ cDNA constructs were expressed, and the ability of chimeric proteins to mediate C5a, IL-8, and fMLP-induced release of inositol phosphate in transfected Cos-7 cells was tested. The results showed that short stretches of residues 154 to residue 167 and from residue 174 to residue 195 of $G{\alpha}_{16}$ contribute to efficient coupling to the C5a receptor. On the other hand, a stretch of amino acid residues 220-240 of $G{\alpha}_{16}$ that is necessary for interacting with C5a receptor did not play any role in the interaction with IL-8 receptor. However, a stretch from residue 155 to residue 195 of $G{\alpha}_{16}$ was found to be crucial for efficient coupling to IL-8 receptor in concert with C-terminal 30 amino acid residues of this ${\alpha}$ subunit. Coupling profiles of a variety of chimeras, composed of $G{\alpha}_{11}G{\alpha}_{16}$ to fMLP receptor indicate that the C-terminal 30 amino acids are most critical for the coupling of $G{\alpha}_{16}$ to fMLP receptor. Taken together, $G{\alpha}_{16}$ subunit recruits multiple and distinctive coupling regions, depending on the type of receptors, to interact.

• 한국식품위생안전성학회:학술대회논문집
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• 한국식품위생안전성학회 2002년도 춘계학술발표대회 및 심포지움
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• pp.215-215
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• 2002

Catalytic subunit of pyruvate dehydrogenase phosphatase (PDPc) has been suggested to have three major funational domains such as dihydrplipoamide adetyltransferase(E2)-binding domain, regulatory subunit of PDP(PDP)r-binding domain, and calcium-binding domain. In order to identify functional domains, recombinant catalytic subunit of pyruvate dehydrogenase phosphatase(rPDPc) was expressed in E. coli JM101 and purified to near homogeneity using the unique property of PDPc: PDPc binds to the inner lipoyl domain (L2) of E2 of ppyruvate dehydrogenase complex (PDC) in the presence of Ca+2, not under EGTA. PDPc was limited-proteolysed by typsin, chymotypsin, Arg-C, and elastase at pH 7.0 and 30C and N-terminal analysis of the fragments was done. Chymotrypsin, trypsin, and elastase made two major fragments: N-terminal large fragment, approx. 50kD and C-terminal small fragment, approx.10 kDa. Arg-C made three major fragments: N-terminal fragment, approx. 35kD, and central fragment, approx. 15 kD, and C-terminal fragment, approx. 10 kD. This study strongly suggest that PDPc consists of three major functional domains. However, further study should be necessary to identify the functional role.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권1호
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• pp.73-77
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• 2002

The Sec61 trimeric complex ($\alpha$,$\beta$, and ${\gamma}$ subunits) is one of the Sec-complex responsible for post-translational protein translocation across the endoplasmic reticulum membrane in diverse organisms. In this study, a cDNA encoding the Sec61p ${\gamma}$ subunit homologue was isolated from the cDNA library of the mole cricket, Gryllotalpa orientalis. Sequence analysis of a 442-bp cDNA clone showed it to contain an open reading frame of 68 amino acid residues consisted of 204-bp. The homologues of the gene were found in the GenBank database in a diverse organism including insect, mammals, fungi, and plants. The deduced amino acid sequence of Sec61p ${\gamma}$ subunit homologue of the mole cricket showed the highest homology to the gene of the singly known insect, Drosophila melanogester (93% identity), and the least homology to that of the baker's yeast, Saccharomyces cerevisiae (37.2%). Phylogenetic analysis also confirmed a close relationship between the insect Sec61p ${\gamma}$ subunit homologues of G. orientalis and D. melanogester. Hydropathy analysis of the cricket mole and published other data suggested that the hydrophobic segment close to C-terminus is predicted to be the putative membrane anchor, Multiple alignment of the Sec61p ${\gamma}$ subunit homologue among several organisms showed the presence of several conserved domains including the conserved proline at position 28.