CHO 세포에서 누에 혈림프 유래 Storage-protein 2의 세포응집 및 세포사멸 억제 효과

임진혁(Jin-Hyuk Lim),차현명(Hyun-Myoung Cha),김지훈(Z-Hun Kim),최용수(Yong-Soo Choi),김동일(Dong-Il Kim) 한국생물공학회 2016 KSBB Journal Vol.31 No.1

Chinese hamster ovary (CHO) cells have been widely used for production of various recombinant proteins such as cytokines and monoclonal antibodies. The cell aggregation and cell death in CHO cell culture directly affect cell viability, and productivity and quality of products. In this study, we investigated preventing effects of storage-protein 2 (SP2) derived from silkworm hemolymph on cell aggregation and cell death in CHO cell culture producing albumin-erythropoietin (Alb-EPO). The viable cell density in the culture supplemented with 2 mg/mL SP2 was 1.71-fold higher than that in control culture. Increased titer of Alb-EPO was also found in the culture with SP2. Morphology of CHO cells in SP2 supplemented cultures did not differ from that of control. In addition, the cell aggregation rate of the SP2 cultures was reduced 20% compared to the control. Finally, we confirmed that the apoptosis was strongly suppressed by addition of SP2 in the cultures. These results clearly demonstrate that SP2 can be served as an effective supplement for enhancing titer of Alb-EPO via reducing cell aggregation and cell death.

α2,6-Sialyltransferase 과발현을 통한 인간형 시알산 부가 hCTLA4-Ig 생산 CHO 세포주 제작

임진혁(Jin-Hyuk Lim),차현명(Hyun-Myoung Cha),박혜진(Heajin Park),김하형(Ha Hyung Kim),김동일(Dong-Il Kim) 한국생물공학회 2017 KSBB Journal Vol.32 No.3

Sialylation is important in producing therapeutic proteins such as antibody, cytokine and fusion protein. Thus, enhancement of sialylation is usually performed in CHO cell cultures. α2,6-Sialyltransferase (ST), which plays a key role in the attachment of α2,6-sialic acid, is present in human cells but not in Chinese hamster ovary (CHO) cells. Overexpression of α2,6-ST can be used for enhancing the degree of sialylation and achieving human-like glycosylation. In this study, we constructed CHO cells producing human cytotoxic T-lymphocyte antigen4-immunoglobulin (hCTLA4-Ig) as well as α2,6- ST. Transfected CHO cells were selected using G418 and stable cell line was established. Profiles of viable cell density and hCTLA4-Ig titer in an overexpressed cell line were similar to those of a wild-type cell line. It was confirmed that the total amount of sialic acid was increased and α2,6-sialic acid was attached to the terminal residues of N-glycan of hCTLA4-Ig by ESI-LC-MS. Compared to 100% of α2,3-sialic acid in wild type cells, 70.9% of total sialylated N-glycans were composed of α2,6-sialic acid in transfected cells. In conclusion, overexpression of α2,6-ST in CHO cells led to the increase of both the amount of total sialylated N-glycan and the content of α2,6- sialic acid, which is more resemble to human-like structure of glycosylation.

스마트폰 KPU 메신저 개발

임진혁 ( Jin-hyuk Lim ),조효준 ( Hyo-jun Cho ),조숙희 ( Suk-hee Cho ),노영주 ( Young J Rho ) 한국정보처리학회 2010 한국정보처리학회 학술대회논문집 Vol.17 No.2

최근 스마트폰의 수요가 급증하면서, 사용자들의 편의를 위한 애플리케이션의 필요성도 함께 증가하고 있다. 또한 무선 랜(wi-fi)이 제공되는 지역도 점점 늘어나는 추세이다. 이러한 흐름의 일환으로, 우리는 어디서든 사용이 가능하며, 우리가 속한 대학에 특화된 스마트폰용 메신저를 개발하였다. 스마트폰의 무선 랜(Wi-fi)기능을 이용하여 문자, 음성, 파일 전송 등 이동성을 살린 메신저는 학생들과 교직원들이 편리하게 사용 할 수 있어 학교에서 일어나는 활동에 적합화되어 있다.

날개 밑면에서 비균일 분출을 주었을 때 날개의 양항특성에 관한 연구

임진혁(Jin-Hyuk Lim),김학봉(Hark-Bong Kim) 한국항공우주학회 2000 韓國航空宇宙學會誌 Vol.28 No.1

CHO 세포의 2단계 배양을 통한 Albumin-erythropoietin의 시알산 증대

임진혁(Jin-Hyuk Lim),신수아(Soo-Ah Shin),차현명(Hyun-Myoung Cha),김동일(Dong-Il Kim) 한국생물공학회 2016 KSBB Journal Vol.31 No.4

In glycoprotein, Terminal sialic acid residues of Nlinked glycan are imperative things because they prevent the recognition from asialoglycoprotein-receptor that affect the half-life of glycoproteins. So establishment of culture process for enhancing sialic acid is important to maximize sialic acid contents of glycoprotein. In this study, we investigated effects of biphasic culture of Chinese hamster ovary (CHO) cells producing albumin-erythropoietin to increase sialylation. Biphasic cultures were performed with shift of CO₂ concentrations and temperatures at day 5 when viable cell density was decreased and sialidase was started to be released by cell lysis. The examined temperature set points were 33, 35 and 37℃ respectively and the CO₂ concentration was 1, 5, 10 and 15%. We confirmed that sialidase activity was the lowest in biphasic culture that was shifted from normal culture condition to 1% of CO₂ and 33℃ on day 5. However, the temperature and concentration of CO₂ have little effect on activity of α2,3-sialyltransferase. Also, sialic acid contents were enhanced 1.13-fold higher than that in control culture. In conclusion, Biphasic cultivation in CHO cells led to inhibition of sialidase activity and increases of sialylated glycan.

수평 배수재로서 순환골재와 쇄석의 활용 방안

이달원,임진혁,Lee, Dal-Won,Lim, Jin-Hyuk 한국농공학회 2010 한국농공학회논문집 Vol.52 No.6

In this study, laboratory model test on utilization of recycled aggregates and crushed stone as horizontal drains to use alternative material of sand in soft ground is practiced. The coefficient of permeability of the recycled aggregates and crushed stone showed largely 1.2~5.1 times and 2.0~3.3 times greater than sand, respectively. The horizontal coefficient of permeability in case of installing the horizontal perforated drain pipe showed largely 1.9~6.8 times more than the case of not installing. The drainage distance showed 1.7~1.8 times greater than sand. When a degree of consolidation is 90 %, there is no delay of consolidation in SCP and PVD improvement sections. Therefore, it is proven that the field applicability is excellent. Also, the suitable quality management criterion is presented to make use of a horizontal drains in soft ground on the basis of analysis of the physical and environmental characteristics.

CHO 세포 배양에서 UDP-N-acetylglucosamine의 합성 증진을 통한 albumin-erythropoietin의 시알산 증대

한혜진(Hye-Jin Han),이지희(Ji-Hee Lee),차현명(Hyun-Myoung Cha),임진혁(Jin-Hyuk Lim),김동일(Dong-Il Kim) 한국생물공학회 2021 KSBB Journal Vol.36 No.1

Sialylation is a major factor to determine half-life of glycoproteins and sialic acid content of glycoprotein was effectively increased by supplementation of nucleotide sugar precursors during cell cultures. So it is necessary to investigate the effect on glycan may be different when two or more precursors are fed in combination. Albumin-erythropoietin (Alb-EPO) can form a tetra-antennary structure and up to 14 sialic acids can be attached depending on the antennary structure of glycan. It is possible to increase the sialic acid contents of Alb-EPO by promoting the formation of the antennary structure of glycans. In this study, uridine and N-acetylglucosamine (GlcNAc) were added to Chinese hamster ovary (CHO) cell cultures to enhance the synthesis of uridine diphosphate N-acetylglucosamine (UDP-GlcNAc). Also, manganese ion, which is a cofactor of glycosyltransferases or UDPGlcNAc biosynthesis, was added in the form of MnCl₂. By optimizing the feeding concentrations of uridine and GlcNAc with response surface methodology based on central composite design to reduce the negative impact on cell growth and productivity. Cell growth was observed similar and then productivity and sialic acid content of Alb-EPO were enhanced 1.21-fold and 1.69-fold higher than that of the control, respectively. These results suggest that the combined feeding of uridine, GlcNAc, and MnCl₂ is an effective strategy to enhance the sialic acid content of glycoproteins in CHO cell cultures.

유전자재조합 CHO 세포에서 Histone Deacetylase Inhibitor를 이용한 Albumin-erythropoietin 생산성 증진

김수진(Su-Jin Kim),서준석(Joon-Serk Seo),최성훈(Sung-Hun Choi),차현명(Hyun-Myoung Cha),임진혁(Jin-Hyuk Lim),신수아(Soo-Ah Shin),김동일(Dong-Il Kim) 한국생물공학회 2015 KSBB Journal Vol.30 No.1

Chinese hamster ovary (CHO) cells are the most widely used mammalian host for the commercial production of recombinant proteins. However, they show relatively low yields of recombinant proteins in comparison with microbial cells. Various strategies have been tried to overcome this drawback. The acetyl moieties are attached to the N-terminus of histone by histone acetyltransferase (HAT) while histone deacetylase (HDAC) removes histone-bound acetyl groups. HDAC inhibitor (HDACi), such as sodium butyrate, sodium propionate and valproic acid, can enhance specific productivity of CHO cells. Human albumin-erythropoietin (Alb-EPO) is a novel 105 kDa protein comprising recombinant human EPO fused to human albumin. In this study, we examined the effects of HDACi on the production of Alb-EPO in CHO cells with various concentrations in the range of 0-1 mM. The results showed that sodium butyrate was found to be the best HDACi for enhancing productivity. It enhanced not only the production of Alb-EPO but also the apoptosis of recombinant CHO cells.

연약지반에서 수평유공관 간격의 설계방법

이달원 ( Lee Dal Won ),임진혁 ( Lim Jin Hyuk ),김시중 ( Kim Si Jung ),이정준 ( Lee Jung Jun ),오경훈 ( Oh Gyeong Hoon ) 한국농공학회 2009 한국농공학회 학술대회초록집 Vol.2009 No.-

본 연구에서는 연약지반에서 수평배수재로서 순환골재와 쇄석을 사용하였을 경우에 배수성능 부족으로 인한 압밀지연 현상을 분석하고, 동수경사와 매트저항을 고려한 합리적인 수평유공관 간격의 설계방법을 비교분석하고자 한다. 1. 수평배수층의 간극수가 원활히 배출되기 위한 합리적인 배수거리(L)는 배수층의 두께가 증가할수록 직선적으로 증가하고, 순환골재는 모래보다 1.7배, 쇄석은 1.8배 정도 더 크게 나타났다. 따라서 모래와 동일한 조건에서 순환골재와 쇄석은 유공관 간격을 크게 할 수 있기 때문에 공사비와 공기를 단축시킬 수 있다. 2. 침하속도(S)가 증가함에 따라 동수경사(h_w)는 직선적으로 증가하고, 배수거리(L)은 침하속도가 0.5㎝/day 까지는 급격하게 감소하였다. 시험시공 구간에서 적정한 배수거리는 모래는 99m, 순환골재와 쇄석은 167-179m 범위로 나타났으나, 성토기간중에 압밀침하량이 크게 발생하고, 부등침하 및 장비주행에 따른 지지력 확보를 위한 여유두께를 감안하여 수평배수층의 두께(H_m) 및 배수거리를 결정하여야 할 것으로 판단된다. 3. SCP와 PBD개량구간에서 압밀도가 90%일 때 압밀지연은 없는 것으로 나타났고, 수평배수층의 두께가 증가할수록 배수저항은 점차로 감소하여 순환골재와 쇄석은 거의 유사하고, 모래는 순환골재와 쇄석보다 2.9-3.3배 정도 크게 나타났다. 4. 간격비(n)가 10에서 20으로 증가할 경우에 배수저항은 약 8배 정도, 드레인 타입간격(d)이 1.0m에서 2.0m로 증가할 때 약 3-4배 정도 급격하게 감소하였고, 매트저항이 작을 경우에 수평거리에 따른 압밀도는 큰 차이를 나타내지 않아 유공관 간격 및 드레인 타입간격 검토시 설계자료로서 이용할 수 있을 것으로 판단된다.

FEM해석 기반 스퍼기어 펌프의 실험적 검증에 대한 연구

이찬우,김상유,이서한,김재열,임진혁,Lee, Chan-Woo,Kim, Sang-Yu,Lee, Seo-Han,Kim, Jae-Yeol,Lim, Jin-Hyuk 한국기계가공학회 2022 한국기계가공학회지 Vol.21 No.6

This work investigated the performance improvement of a medium-pressure fixed-displacement-type SPUR gear pump, which is mainly used in the machine tool industry. The 3D CFX analysis and IS technique were applied using ANSYS (commercial FEM code) and compared with experimental results to ensure the reliability of the analysis. In addition, the performance improvement of the pump was obtained using the theoretical volumetric displacement equation, and the gear tooth width was changed. The pressure flow performance curves were compared, and the results were analyzed according to the width of the gear teeth. This is a factor that can cause irregular flow, vibration, and noise inside the gear pump owing to friction between the housing and gear pump.