• 한국결정학회지
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• 제5권1호
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• pp.20-23
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• 1994

대장균의 IciA 단백질은 DnaA 단백질의 작용장소에 결합하여 DNA의 복제가 개시되는 것을 막는다. 따라 서 IciA단백질은 세포주기의 주요 단계에서 결정적인 역할을 한다. 이러한 IciA 단백질의 구조와 기능간의 관 계를 연구하기 위하여 X-선 결정학을 이용하여 삼차원 구조를 결정하고자 한다. 그 첫 단계로 IciA단백질 결정화를 시도하였다. sodium formate를 침전제로 이용하여 결정을 얻을 수 있었다.

• Fisheries and Aquatic Sciences
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• 제17권4호
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• pp.455-459
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• 2014

A feeding trial was conducted to determine the optimum dietary protein requirement of young far eastern catfish Silurus asotus. Five isocaloric diets were formulated to contain graded levels of protein (35, 40, 45, 50, and 55%). Triplicate groups of fish (initial body weight of 44 g) were hand-fed to apparent satiation for 9-weeks. Weight gain and specific growth rate of fish fed 55% protein diet were significantly higher than those of fish fed 35 and 40% protein diets, but not significantly different from those of fish fed 45 and 50% protein diets. The feed efficiency of fish fed 50 and 55% protein diets was significantly higher than that of fish fed 35, 40 and 45% protein diets. The protein efficiency ratio of fish fed 40% protein diet was significantly higher than that of fish fed 45, 50 and 55% protein diets, but not significantly different from that of fish fed 35% protein diet. The dietary protein level significantly affected whole body lipid and moisture contents. The results of this study suggest that the 45% protein in the diet is optimal for maximum growth of young far eastern catfish weighing in the range of 44 to 227 g.

• 한국식품과학회지
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• 제8권4호
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• pp.263-272
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• 1976

According to the intercombined review of chemical and biological investigation it has been noted that the metabolizable energy per gram dietary protein of mixed diet of daily intake patterned by Korean population has been found 3.4-3.6 Cal., which entails 10-12% level of the protein calorie percentage of total metabolizable energy, the biological value being fallen within the scope 63-73. The structure of dietary protein has revealed that the lysine and isoleucine were primary limiting amino acids and threonine secondary limiting as a general trend, however, it is assumed that the ultimate nutritional effect of dietary protein might be restricted uniformly among regions by the amount of lysine, since the lysine availability has been yielded as low as 72-82% level. As for the net protein utillization NPUst falls in the range of 52-62 and the NPUop 47-58. In either part the mountainous region has demonstrated lowest value and the urban area highest, these trend being obviously associated with the ratio of animal protein relative to the vegetable origin. The net dietary protein calorie percentage (NDpCal %) has been found within the range of 5-7 that may be capable of meeting the requirement for the maintenance of adult, though for the growth it is insufficient. Present level of total caloric intake would not influence on the fate of protein value of prevailing regional diet in terms of caloric restriction, since the present intake of food energy is higher than the lower limit of caloric intake that would impair the biological performance of dietary protein fed ad libitum basis. Based on the protein efficiency, the adequacy of current level of protein intake was analyzed in terms of utilizable protein, and it has been demonstrated that the 37.8g of utilizable protein in the fishery region and 38.2g in the mountainous region were bellow the FAO recommendation. Accordin to the hematological study it may be interpreted that the anemic symptoms of the mountainous region has some possibility of being related to the inferior status of dietary protein in quality as well as in quantity.

• 한국식품과학회지
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• 제18권3호
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• pp.204-209
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• 1986

번데기 단백질의 이용성을 증진시킬 목적으로 농축 단백질을 조제하여 중요한 성질인 기능성을 대두 단백질과 비교하였다. 번데기 농축단백질은 대두 농축단백질보다 지방 흡수력이 더 높았으며, 용해도와 수분 흡수력은 낮았다. 유화성은 62.8%로 번데기 농축단백질이 더 높았으며, 유화력도 307ml/g으로 역시 높게 나타났다. 또한 $80^{\circ}C$로 가열한 후의 유화안정성도 번데기 농축단백질이 65.8%로 대두 농축단백질보다 더 높게 나타났다. 포말성은 번데기 농축단백질이 더 낮았으며 포말안정성은 달걀알부민보다, 번데기, 대두 농축단백질이 더 낮았고, $5{\sim}7%$사이에 점도 증가 현상이 크게 나타났다. 이상의 실험결과에서 나타난 번데기 농축단백질의 높은 지방 흡수력과 유화성은 유화력을 이용한 식품제조에 좋은 단백질원으로서 이용이 가능하리라고 사료된다.

• Molecules and Cells
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• 제27권5호
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• pp.577-582
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• 2009

The development of a high-throughput functional genomic screening provides a novel and expeditious approach in identifying critical genes involved in specific biological processes. Here we describe a cell-based cDNA screening system to identify the transcription activators of BiP, an endoplasmic reticulum (ER) chaperone protein. BiP promoter contains the ER stress element which is commonly present in the genes involved in unfolded protein response (UPR) that regulates protein secretion in cells. Therefore, the positive regulators of BiP may also be utilized to improve the recombinant protein production through modulation of UPR. Four BiP activators, including human UDP-glucose:glycoprotein glucosyltransferase 1 (HUGT1), are identified by the cDNA screening. Overexpression of HUGT1 leads to a significant increase in the production of recombinant erythropoietin, interferon ${\gamma}$, and monoclonal antibody in HEK293 cells. Our results demonstrate that the cDNA screening for BiP activators may be effective to identify the novel BiP regulators and HUGT1 may serve as an ideal target gene for improving the recombinant protein production in mammalian cells.

• Biomolecules & Therapeutics
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• 제13권2호
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• pp.101-106
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• 2005

The generation of secretory IgA antibodies (Abs) for specific immune protection of mucosal surfaces depends on stimulation of the mucosal immune system, but this is not effectively achieved by parenteral or even oral administration of most soluble antigens. Thus, to produce a possible vaccine antigen against urinary tract infections, the uropathogenic E. coli (UPEC) adhesin was genetically coupled to the heat-labile Escherichia coli enterotoxin A2B (ltxa2b) gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimH/ltxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. The chimeric protein was then purified by applying the affinity chromatography. The purified chimeric protein was confirmed by SDS-PAGE and westem blotting using antibodies to the maltose binding protein (MBP) or the heat labile E. coli subunit B (LTXB), plus the N-terminal amino acid sequence was analyzedd. The orderly-assembled chimeric protein was confirmed by a modified $G_{M1}$-ganglioside ELISA using antibodies to adhesin. The results indicate that the purified chimeric protein was an Adhesin/LTXA2B protein containing UPEC adhesin and the $G_{M1}$-ganglioside binding activity of LTXB. thisstudy also demonstrate that peroral administration of this chimeric immunogen in mice elicited high level of secretory IgA (sIgA) and serum IgG Abs to the UPEC adhesin. The results suggest that the genetically linked LTXA2B acts as a useful mucosal adjuvant, and that adhesin/LTXA2A chimeric protein might be a potential antigen for oral immunization against UPEC.

• Asian-Australasian Journal of Animal Sciences
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• 제23권5호
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• pp.598-606
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• 2010

This study investigated the nutritional quality of soybean meal (SBM) fermented by Aspergillus ($FSBM_A$) and/or followed by Lactobacillus fermentation ($FSBM_{A+L}$). Both fermented products significantly improved protein utilization of SBM with higher trichloroacetic acid (TCA) soluble true protein content, in vitro protein digestibility and available lysine content, especially in $FSBM_{A+L}$. Moreover, $FSBM_{A+L}$ produced a huge amount of lactic acid resulting in lower pH as compared to the unfermented SBM or soybean protein concentrate (SPC) (p<0.05). $FSBM_A$ and $FSBM_{A+L}$ raised 4.14% and 9.04% of essential amino acids and 5.38% and 9.37% of non-essential amino acids content, respectively. The ${\alpha}$-galactoside linkage oligosaccharides such as raffinose and stachyose content in $FSBM_A$ and $FSBM_{A+L}$ decreased significantly. The results of soluble protein fractions and distribution showed that the ratio of small protein fractions (<16 kDa) were 42.6% and 63.5% for $FSBM_A$ and $FSBM_{A+L}$, respectively, as compared to 7.2% for SBM, where the ratio of large size fractions (>55 kDa, mainly ${\beta}$-conglycinin) decreased to 9.4%, 5.4% and increased to 38.8%, respectively. There were no significant differences in ileal protein digestibility regardless of treatment groups. SPC inclusion in the diet showed a better protein digestibility than the SBM diet. In summary, soybean meal fermented by Aspergillus, especially through the consequent Lactobacillus fermentation, could increase the nutritional value as compared with unfermented SBM and is compatible with SPC.

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1216-1221
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• 2006

A protein array was fabricated for a miniaturized immunoassay using microcontact printing ($\mu$CP). A polydimethylsiloxane (PDMS) stamp with a 5 $\mu$m$\times$5 /$\mu$m dimension was molded from a silicon master developed by photolithography. Under optimal fabrication conditions, including the baking, incubation, and exposure time, a silicon master was successfully fabricated with a definite aspect ratio. An antibody fragment was utilized as the ink for the $\mu$CP, and transferred to an Au substrate because of the Au-thiol (-SH) interaction. The immobilization and antibody-antigen interaction were investigated with fluorescence microscopy. When human serum albumin (HSA) was applied to the protein array fabricated with an antibody against HSA, the detection limit was 100 pg/ml of HSA when using a secondary antibody labeled with a fluorescence tag. The fabricated protein array maintained its activity for 14 days.

• 농업과학연구
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• 제5권2호
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• pp.56-67
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• 1978

본(本) 실험(實驗)은 대두(大豆)의 성숙중(成熟中) 종실(種實)의 발육(發育)과 단백질(蛋白質) 및 그 구성분(構成分)의 변화(變化)에 관한 고저단백질(高低蛋白質) 품종간(品種間)의 생리적(生理的) 차이를 밝히고자 고단백품종(高蛋白品種) 서해(西海)20호(號), 중단백품종(中蛋白品種) 광교(光敎) 및 저단백품종(低蛋白品種) Shelbv를 공시(供試)하여 종실(種實)의 발육상황(發育狀況), 단백질(蛋白質) 및 지방함량(脂肪含量) 변화(變化), disc polyacrylamide gel 전기영동법(電氣泳動法)에 의한 단백질구성분(蛋白質構成分)의 조성변화(組成變化) 등을 조사(調査)하였던 바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1. 대두(大豆) 종실(種實)은 대체(大體)로 개화후(開化後) 22일(日)까지 완만(緩慢)히 그 이후(以後) 20~30일간(日間) 직선적(直線的)으로 급속(急速)히, 그후 5~15일간(日間) 서서히 건물중(乾物中)이 증가(增加)되어 최고(最高)에 달하며, 개화후(開化後) 12일(日)부터 27일(日)까지 단백질함량(蛋白質含量)은 급속(急速)히 감소(減少)되는 반면에 지방함량(脂肪含量)은 급격(急激)히 증가(增加)되고 그 후부터 개화후(開化後) 40~47일(日)까지는 단백질(蛋白質)과 지방함량(脂肪含量) 모두 서서히 증가(增加)된 후 성숙기(成熟期)까지 큰 변화(變化)가 없었다. 2. 고단백품종(高蛋白品種) 서해(西海)20호(號)는 광교(光敎) 및 Shelby에 비해 전(全) 성숙기간(成熟期間)에 대한 비율(比率)로 보아 성숙초기(成熟初期)의 단백질(蛋白質) 함량(含量) 감소기간(減少期間)이 짧고 감소율(減少率)도 적었으며 그후 단백질함량(蛋白質含量) 증가기간(增加期間)이 길고 증가율(增加率)도 큰 특성(特性)을 보였으나, 지방(脂肪) 축적(蓄積)은 일찍 정지(停止)되었다. 3. 저단백(低蛋白) 고지방품종(高脂肪品種) Shelby는 서해(西海)20호(號) 및 광교(光敎)에 비해 전(全) 성숙기간(成熟期間)에 대한 단백질함량(蛋白質含量) 감소기간(減少期間)이 길고 증가기간(增加期間)은 짧았으며, 지방함량(脂肪含量)의 증가기간(增加期間)이 특히 길었다. 4. 종실(種實)의 성숙과정중(成熟過程中) 단백질구성분(蛋白質構成分)의 변화양상(變化樣相)은 품종간(品種間) 차(差)가 뚜렷하였고, 완숙종실(完熟種實)의 단백질구성분(蛋白質構成分)들이 모두 출현(出現)하는 시기(時期)는 종실(種實)의 단백질함량(蛋白質含量) 감소(減少)가 끝난 시기(時期)와 대체(大體)로 일치(一致)되었으며, 상대이동도(相對移動度)가 가장 작은 단백질(蛋白質)(a'=Rm 0.03)이 개화후(開花後) 17일(日)까지는 존재(存在)하였으나 그 이후(以後)에는 없었다. 5. 고단백품종(高蛋白品種) 서해(西海)20호(號)는 광교(光敎) 및 Shelby에 비해 단백질구성분(蛋白質構成分) a($a_1+a_2+a_3$)의 조성비율(組成比率)이 성숙초기(成熟初期)에서부터 계속 높았고 개화후(開花後) 47일(日)까지 계속 증가(增加)되었으나, 광교(光敎)와 Shelby에서는 구성분(構成分) a의 조성비율(組成比率)이 개화후(開花後) 27일경(日頃) 이후(以後) 거의 변화(變化)되지 않았다.

• 생명과학회지
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• 제23권8호
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• pp.978-983
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• 2013

Kinesin-II는 다양한 운반체들을 미세소관을 따라 운반하는 motor 단백질의 하나이다. Kinesin-II는 두 개의 motor 단백질 KIF3A와 KIF3B, 그리고 motor 단백질의 말단에 결합하는 kinesin superfamily-associated protein 3 (KAP3)로 구성되어 있다. KAP3는 Kinesin-II의 기능에 중요한 역할을 하는 것으로 알려져 있으나 명확한 기능은 아직 밝혀지지 않았다. 본 연구에서 KAP3와 결합하는 단백질을 분리하기 위하여 효모 two-hybrid system을 사용하여 탐색한 결과 HS-1-associated protein X-1 (HAX-1)을 분리하였다. KAP3은 HAX-1의 C-말단 부위와 결합하며, HAX-1은 KAP3의 C-말단부위와 결합함을 효모 two-hybrid assay로 확인하였다. 그러나, HAX-1는 KIF3A, KIF3B, KIF5B, 그리고 kinesin light chain (KLC)과는 결합하지 않았다. KAP3와 HAX-1의 단백질 결합은 glutathione S-transferase (GST) pull-down assay와 공동면역침강으로 추가 확인하였다. 생쥐의 뇌 파쇄액을 HAX-1 항체와 KIF3A 항체로 면역침강을 행한 결과 Kinesin-II의 구성단백질인 KIF3B와 KAP3가 같이 침강하였다. 이러한 결과들은 KAP3가 Kinesin-II와 HAX-1의 결합을 매개한다는 것을 시사한다.