• Journal of Microbiology and Biotechnology
• /
• 제2권1호
• /
• pp.46-49
• /
• 1992

The availability of Phaffia rhodozyma as an astaxanthin sources in the aquaculture industry is limited because of the low carotenoid content of natural isolate. In this study, we have used the protoplast fusion technique to construct cell hybrids with an increased content of astaxanthin from P. rhodozyma. Cell hybrids (F307 and F406) obtained were very stable and produced considerably more astaxanthin (> 1 mg/g yeast) than the wild parent. Karyogamy was confirmed by the isolation of recombinants after mitotic segregation of parental auxotrophic genetic markers, the increased amount of chromosomal DNA/cell and the presence of single nucleus/cell.

• Bulletin of the Korean Chemical Society
• /
• 제27권2호
• /
• pp.281-285
• /
• 2006

Microbial fuel cells (MFC) stacked with bipolar plates have been constructed and their performance was tested. In this design, single fuel cell unit was connected in series by bipolar plates where an anode and a cathode were made in one graphite block. Two types of bipolar plate stacked MFCs were constructed. Both utilized the same glucose oxidation reaction catalyzed by Gram negative bacteria, Proteus vulgaris as a biocatalyst in an anodic compartment, but two different cathodic reactions were employed: One with ferricyanide reduction and the other with oxygen reduction reactions. In both cases, the total voltage was the mathematical sum of individual fuel cells and no degradation in performance was found. Electricity from these MFCs was stored in a supercapacitor to drive external loads such as a motor and electric bulb.

• 폴리머
• /
• 제33권2호
• /
• pp.118-123
• /
• 2009

본 연구는 신경손상 모델에서 신경재생을 유도하는 슈반세포(SC)의 배양에 케라틴이 미치는 영향을 확인하기 위한 실험으로써, 친수성 아미노산으로 구성된 케라틴과 PLGA를 혼합하여 케라틴/PLGA 필름을 0, 10, 20, 그리고 50 wt%가 되도록 제조하여, 케라틴 안에 존재하는 다양한 단백질 및 신호전달물질이 슈반세포의 증식, 부착형태 그리고 표현형 유지에 미치는 영향을 확인하였다. 세포의 배양 방법은 손쉽고 순수한 세포 분리가 가능한 Morrissey의 방법을 이용하였고 필름의 젖음성 확인을 위하여 접촉각 측정을 실시하였으며, 정해진 시간에 세포를 계수하여 케라틴 함량에 따른 세포 성장차이를 비교하였다. 케라틴/PLGA 필름에서의 세포의 부착 거동 및 세포 형태를 SEM을 통하여 확인하였고 슈반세포의 표현형 유지를 확인하기 위해 RT-PCR을 수행하였다. 실험 결과, 다른 함유량과 비교 시 케라틴 10 또는 20 wt%가 함유된 케라틴/PLGA 필름이 SC 성장 및 표현형 유지에 긍정적인 영향을 미침을 확인하였다.

• Biomolecules & Therapeutics
• /
• 제29권3호
• /
• pp.282-289
• /
• 2021

A novel coronavirus, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), caused a worldwide pandemic. Our aim in this study is to produce new fusion inhibitors against SARS-CoV-2, which can be the basis for developing new antiviral drugs. The fusion core comprising the heptad repeat domains (HR1 and HR2) of SARS-CoV-2 spike (S) were used to design the peptides. A total of twelve peptides were generated, comprising a short or truncated 24-mer (peptide #1), a long 36-mer peptide (peptide #2), and ten peptide #2 analogs. In contrast to SARS-CoV, SARS-CoV-2 S-mediated cell-cell fusion cannot be inhibited with a minimal length, 24-mer peptide. Peptide #2 demonstrated potent inhibition of SARS-CoV-2 S-mediated cell-cell fusion at 1 µM concentration. Three peptide #2 analogs showed IC50 values in the low micromolar range (4.7-9.8 µM). Peptide #2 inhibited the SARS-CoV-2 pseudovirus assay at IC50=1.49 µM. Given their potent inhibition of viral activity and safety and lack of cytotoxicity, these peptides provide an attractive avenue for the development of new prophylactic and therapeutic agents against SARS-CoV-2.

• BMB Reports
• /
• 제46권12호
• /
• pp.606-610
• /
• 2013

Glucagon like peptide-1 (GLP-1) regulates glucose mediated-insulin secretion, nutrient accumulation, and ${\beta}$-cell growth. Despite the potential therapeutic usage for type 2 diabetes (T2D), GLP-1 has a short half-life in vivo ($t_{1/2}$ <2 min). In an attempt to prolong half-life, GLP-1 fusion proteins were genetically engineered: GLP-1 human serum albumin fusion (GLP-1/HSA), AGLP-1/HSA which has an additional alanine at the N-terminus of GLP-1, and AGLP-1-L/HSA, in which a peptide linker is inserted between AGLP-1 and HSA. Recombinant fusion proteins secreted from the Chinese Hamster Ovary-K1 (CHO-K1) cell line were purified with high purity (>96%). AGLP-1 fusion protein was resistant against the dipeptidyl peptidase-IV (DPP-IV). The fusion proteins activated cAMP-mediated signaling in rat insulinoma INS-1 cells. Furthermore, a C57BL/6N mice pharmacodynamics study exhibited that AGLP-1-L/HSA effectively reduced blood glucose level compared to AGLP-1/HSA.

• 한국미생물학회:학술대회논문집
• /
• 한국미생물학회 2001년도 추계학술대회
• /
• pp.97-101
• /
• 2001

The fusion between viral envelope and target cell membrane is a central step of viral infection, and the fusion proteins located at viral envelope mediate such process. Gp41 of HIV is one of the fusion proteins whose structure and mechanism of membrane fusion had been extensively studied. Functionally important motives of gp41 are the N-terminus fusion peptide, the coiled-coil and the membrane proximal C-peptide regions. The role of these regions during the fusion process had been thoroughly examined. Specially, insertion of the fusion peptide into membrane and conformational change of the coiled-coil and C-peptide regions are assumed to be critical for the fusion mechanism. In addition, the coiled-coil region has been shown to interact with membrane, and the C-peptide region regulates the interaction in a dose dependent manner. Furthermore, fusion defective mutations of the coiled-coil region dramatically changed its binding affinity to membrane. These results suggested that the membrane binding property of the coiled-coil region is important for the fusion activity of gp41, and such property could be modulated by the interaction with the C-peptide region.

• 한국수정란이식학회:학술대회논문집
• /
• 한국수정란이식학회 2004년도 제4회 발생공학 국제심포지움 및 학술대회
• /
• pp.115-115
• /
• 2004

• 한국동물학회지
• /
• 제26권4호
• /
• pp.235-251
• /
• 1983

배양한 계배 근원세포의 융합기작을 밝혀보기 위해서 분화과정에 있는 근세포를 lactoperoxidase를 촉매로 써서 막표면단백질을 iodination하여 본 결과, 융합의 과정에서 막표면단백질의 정성적 및 정량적 변화를 볼 수 있었다. 융합전의 세포에서 12개의 주요단백질을 검출할 수 있었는데, 융합시의 세포에서는 165K와 93K의 단백질이 새롭게 나타났으며 동시에 245K 단백질의 감소와 저분자 단백질의 증가를 볼 수 있었다. 이 고분자 단백질의 감소는 세포주기와 관계가 있는 것으로 생각되고 있는 세포내 cAMP 수준은 융합에 앞서서 현저한 일시적인 증가를 보였는데, 이와같은 결과는 cAMP의 증가가 세포의 융합의 유발과 관계가 있음을 보여 주는 것이었으며, 분화하는 근원세포에서는 고도의 동조성이 보였다. 아울러, 근세포의 융합과정에서 적어도 4 가지의 iodination된 저분자 단백질을 배양액에서 발견할 수 있었는데, 이들은 막단백질의 가수분해산물로 생각되었고, 역시 세포의 융합과정과 유관할 것으로 추정되었다. 세포막 표면단백질의 변화, 분화과정 중에 배양액 속으로 방출되는 단백질, 융합과 유관한 cAMP의 증가 및 융합과 관련되는 외적 요인의 가능성에 관해서 논의하였다.

• 한국가축번식학회지
• /
• 제20권3호
• /
• pp.307-313
• /
• 1996

This study was conducted to investigate the effect of S-phase synthronized nuclear transfer on the development of nuclear transplant bovine embryos. A blastomere derived from the 16~32 cell stage bovine embryos was transferred into an enucleated metaphase II(MII) oocytes or activated S-phase eggs. From the MII-phase and S-phase nuclear transfer, 6.3%(4/63) and 13.8%(9/65) of nuclear transplant embryos developed to the blastocyst stage, respectively. In the S-phase nuclear transfer, maximal proportion of embryos developed to the blastocyst stage(16.6%) was obtained after the recipient cell was activated 8 h prior to receving a donor nucleus. MII-phase nuclear transplant embryos showed the PCC state of their nuclear at 1.5~2 h after fusion, whereas, S-phase nuclear transplant embryos did not undergo PCC. The result of this study suggests that if blastomeres of unknown cell-cycle-stage are used, S-phase nuclear transplantation through the activation of enucleated oocytes prior to fusion enhances development of nuclear transplant embryos. This result also suggests that the interval time from oocyte activation to cell fusion may affect the development of nuclear transplant embryos.

• 한국양봉학회지
• /
• 제34권1호
• /
• pp.39-46
• /
• 2019

BQCV multi-point PCR was developed as a rapid multiplex detection method for BQCV, one of the viral pathogens of honeybees. It could detect BQCV specific genes qualitative as well as quantitative detection based on ultra-rapid PCR. Three primer pairs (RNA dependent RNA polymerase, capsid protein, 3C like protease) were specifically designed for accurate the detection and were optimized for minimizing the detection time and increasing the sensitivity. Our advanced diagnostic system have the accuracy by lowering the concern about the variation in the BQCV detection site. In addition, it should be an opportunity to identify mutations that are mixed with other viruses.