• 한국미생물·생명공학회지
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• 제17권3호
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• pp.269-272
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• 1989

In order to obtain monoclonal antibody from ascites fluid at sufficiently high purity using a single hydroxylapatite chromatography (HA) a further optimization on its operating variables was carried out. By adjusting the pH of the eluent, the sodium phosphate buffer, to 6.0 from 6.8 and adding CaCl$_2$to 1 mM at the column inlet, the elution molarities (M$_{elu}$) for the desired monoclonal antibody and contaminating proteins can be distinguished from each other with enough resolution. Previously these two groups of proteins co-eluted at the same time at pH 6.8 and without CaCl$_2$. This sin81e step hydroxylapatite chromatography yields the desired antibody pure enough for diagnostic use.

• BMB Reports
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• 제32권3호
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• pp.311-316
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• 1999

Studies in adipocytes indicate that secretion of active lipoprotein lipase (LPL) was strictly regulated by a quality control system in the endoplasmic reticulum (ER). However, there has been no report about the ER chaperones participating in the folding and assembly of LPL. Many chaperones are known to bind unfolded proteins and dissociate from them through the ATP-hydrolyzing reaction. In this study, putative ER chaperones for LPL were determined by affinity chromatography using denatured LPL as an affinity ligand and elution with ATP. BiP, grp94, calreticulin, and another 50 kDa K-D-E-L protein in the ER of rat adipose tissue were bound to denatured LPL and eluted by ATP. Calnexin was bound to denatured LPL; however, it was not eluted by ATP but by acetic acid. These results indicate that, at least, BiP, grp94, calreticulin, calnexin, and the unidentified 50 kDa protein might act as putative chaperones for the proper folding and assembly of LPL in ER.

• Parasites, Hosts and Diseases
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• 제37권1호
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• pp.39-46
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• 1999

As a preliminary study for the explanation of pathobiology of Neodiplostomum seoulense infection. a 54 kDa protease was purified from the crude extract of adult worms by sequential chromatographic methods. The crude extract was subjected to DEAE-Sepharose Fast Flow column, and protein was eluted using 25 mM Tris-HC1 (pH 7.4) containing 0.05. 0.1, 0.2 and 0.4 M NaC1 in stepwise elution. The 0.2 M NaCl fraction was further purified by Q-Sepharose chromatography and protein was eluted using 20 mM sodium acetate (pH 6.4) containing 0.05, 0.1. 0.2 and 0.3 M NaCl, respectively. The 0.1M NaCl fraction showed a single protein band on SDS-PAGE carried out on a 7.5-15% gradient gel. The proteolytic activities of the purified enzyme were specifically inhibited by L-trans-epoxy-succinylleucylamide (4-guanidino) butane (E-64) and iodoacetic acid. The enzyme, cysteine protease. showed the maximum proteolytic activity at pH 6.0 in 0.1 M buffer, and degraded extracellular matrix proteins such as collagen and fibronectin with different activities. It is suggested that the cysteine protease may playa role in the nutrient uptake of N. seoulense from the host intestine.

• Journal of Microbiology
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• 제35권4호
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• pp.327-333
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• 1997

Although extensively characterized in human cells, no heterogeneous nuclear ribonucleoprotein(hnRNP) has been found in the fission yeast Schizosaccharomyces pombe which is amenable to genetic studies and more similar to mammals than Saccharomyces cerevisiae is in terms of RNA processing. As a first step to characterize hnRNPs from S. pombe, attempt was made to find human hnRNP A1 homologs from S. pombe. The RNA molecule (A1 winner) containing the consensus high-affinity hnRNP A1 binding site (UAGGGA/U) was synthesized in vitro and used in an ultraviolet(UV) light-induced protein-RNA cross-linking assay. A number of S, pombe proteins bound to the A1 winner RNA. An approximately 50-kDa protein(p50) cross-linked more efficiently to the A1 winner RNA than other proteins. The p50 protein did not cross-link to a nonspecific RNA, but rather to the A1-5’ SS RNA in which the consensus 5’ splice junction sites of S. pombe introns were abolished. This suggests that the p50 protein, however, did not bind to the single-stranded DNA to shich the human hnRNP A1 could bind and be eluted with 0.5M NaCl. Further analysis should reveal more features of this RNA-binding protein.

• BMB Reports
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• 제33권3호
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• pp.242-248
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• 2000

Phage display of proteins is a powerful tool for protein engineering since a vast library of sequences can be rapidly screened for a specific property. In this study, we develop da new phage display vector that was derived from a pET-25b(+) vector. The pET-25b(+) was modified in order that the expressed protein would have a T7-tag at the amino terminus and GpS (a major coat protein of M13 phage) at the carboxyl terminus. Another vector without the gp8 gene was also constructed. The newly developed phagemid vectors have several advantageous features. First, it is easy to examine whether or not the target proteins are functional and faithfully transported into the periplasmic space. This feature is due to the fact that recombinant proteins are produced abundantly in the pET system. Second, the T7-tag makes it possible to detect any target proteins that are displayed on the surface of filamentous bacteriophage. To verify the utility of the vector, the clones containing the glutathione S-transferase (GST) gene as a target were examined. The result showed that the GST produced from the recombinant vector was successfully transported into the periplasmic space and had the anticipated enzyme activity. Western blot analysis using a T7-tag antibody also showed the presence of the target protein displayed on the surface of the phage. The phages prepared from the recombinant clones were able to bind to glutathione-Sepharose and then eluted with glutathione. These results showed that the new vectors developed in this study are useful for the phage display of proteins.

• 한국균학회지
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• 제17권3호
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• pp.105-113
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• 1989

흰느타리버섯 Pleurotus cornucopiae 중의 단백질을 선택적으로 분리 정제하기 위하여, 출발물질인 AH 4B와 숙신산 무수물을 반응시켜 SAH 4B를 얻은 다음 이에 P-PD을 반응시켜 P-ASAH 4B를 합성하여 친화성 크로마토그래피하였다. 1) SAH 4B겔 중의 succinyl기의 capacity는 겔 1ml당 $9.0{\mu}mol$이었으며, p-ASAH 4B 겔 중의 p-aminoanilinyl기의 capacity는 겔 1ml당 $6.1{\mu}mol$ 이었다. 2) 합성한 P-ASAH 4B겔에 친화성 있는 단백질의 총 겉보기 분자량은 167KD이었으며, 이는 37KD와 130KD단백질의 복합체 이었다. 출발물질인 AH 4B겔에 친화성 있는 단백질의 총 겉보기 분자량은 97.2KD이었으며, 이는 3.2KD, 31KD및 61KD단백질의 복합체 이었다. 3) 합성한 P-ASAH 4B겔에 친화성이 있는 단백질 중의 아미노산 함량은 비극성 아미노산이 44.57%, 극성 아미노산이 24.75%, 양성 아미노산이 21.25% 및 음성 아미노산이 9.43%였고, AH 4B겔에 친화성이 있는 단백질 중의 아미노산 함량은 비극성 아미노산이 44.05%, 극성 아미노산이 29.13%, 양성 아미노산이 13.91% 및 음성 아미노산이 12.91%로 차이가 있었다. 4) 합성한 P-ASAH 4B겔 중의 p-amino-anilinyl기가 AH 4B겔 중의 아미노기보다 양전하를 가진 아미노산을 더 많이 함유하는 단백질을 선택적으로 분리하였다.

• Preventive Nutrition and Food Science
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• 제2권1호
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• pp.42-48
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• 1997

the exocrine pancreatic secretion is an important factor in the maintenance of zinc homeostasis. The daily pancreatic secretion of zinc into the gastrointestinal tract may be two or more times the daily dietary zinc intake. The objective of this study was to examine the distribution of proteins and zinc in pancreatic/biliary fluid following intraperitoneal {TEX}${65}^Zn${/TEX} injection into dietary prepared Sprague-Dawly rats. Distribution of zinc-binding protein in Sephadex G-75 subfractions showed a peak corresponding to the high molecular weight protein standard(<66kDa) in the pancreatic/biliary fluid. Zinc also was associated with the 29~35kDa mole-cular weight proteins. These are similar in size with zinc-containing enzymes, carboxypeptidase A and car-boxypeptidase B. A more remarkable small molecular weight fraction eluted beyond the 6.5kDa standard pro-tein peak. These results show the presence of small molecular weight compound in pancreatic/biliary fluid associated with zinc . These small molecular weight compounds may serve as zinc-binding ligands for the secretion of enogenous zinc into the duodenum. These findings suggest that these lignads may dissociate zinc in the duodenum thus making it vulnerable to complexation with phytate in the upper gastrointestinal tract rendering the zinc unavailable for reabsorption.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2004년도 정기총회 및 제33차 춘계 학술대회
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• pp.198-201
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• 2004

To investigate hydrostatic pressure (HP) effect on myofibrillar protein (Mf) extracted from bovine Semitendinosus muscle, Ca- and Mg-ATPase activities to evaluate denaturation of myosin and actin, and soluble protein contents were observed. In Mf treated with 100 MPa for 5 min was not observed denaturation of myosin and actin. In Mf treated with 200 MPa for 5 min, denaturation of myosin and actin were observed but inactivation rate was low (0.0136 $min^{-1}$). Inactivation rate of myosin and actin was dramatically increased above 300 MPa treatment. However denaturation of myosin and actin was not that critical with duration time. By increasing pressure size, the amount of myosin and actin in soluble protein eluted in 20 mM potassium phosphate buffer (pH 7.0) containing 0.6 M NaCl were decreased. SDS-PAGE of soluble protein released from Mf suspension in 0.1 M NaCl buffer (pH 7.0) showed that low molecular weight proteins (15${\sim}$36 KDa) were released by HP treatment above 200 MPa. From the results, denaturation of myosin and actin, and release of light molecule proteins of Mf were observed by HP treatment over 200 MPa.

• 분석과학
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• 제30권6호
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• pp.348-354
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• 2017

이 연구는 출산 후 1, 3, 6주가 경과한 산모에서 얻은 모유의 단백체 발현 양상과 과 발현 단백질을 검출하는 것을 목적으로 하였다. 샷 건 정량 단백체 분석법을 이용하여 모유 중의 단백질을 동정하였고, 각 수유단계 간에 정량적 비교를 하였다. 각 주의 모유 샘플은 두 명의 산모로부터 얻어진 모유를 혼합하였고, 각 샘플 마다 3회 반복 실험을 하였다. Casein은 모유 내에 가장 많이 존재하는 단백질로서 실험의 정확성을 위하여 제거하였고, 트립신을 이용한 절편 화로 모유 단백질들을 펩타이드로 변환하였다. 처리된 펩타이드들은 역상 C18 미세관 크로마토그래피 및 이온-트랩 질량분석기를 이용하여 분석하였으며, Spectra Counting으로 단백질의 정량적 비교를 하였다. 각 샘플 당, 80-109 개의 단백질을 중복 제거한 후 동정하였다. 당화 단백질, metabolic enzyme, 및 lactoferrin, Carboxylic ester hydrolase, Clusterin을 포함하는 chaperon 효소들이 주로 검출되었다. 각 반복실험에서 재현성 있게 검출되는 63개의 단백질에 대한 정량적 비교분석 결과 25개의 단백질이 통계적으로 유의하게 수유단계에 따라 변화하는 것을 확인할 수 있었고, 특히 Ig lambda-7 chain C region과 Tenascin은 시간에 따라 현저하게 감소하였다. 향후 이와 같은 수유 단계에 따른 모유 내 단백의 변화가 생리적으로 가지는 의미에 관하여 추가적인 연구가 필요하다 생각된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권2호
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• pp.141-145
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• 2000

Entomopathogenic nematodes are being used for insect control. We purified a toxin secreted by the insect-pathogenic bacterium, Xenorhadbus nematophilus, which lives in the gut of entomopathogenic nematodes. Culture broth of X. nematophilus was separated by centrifugation and concentrated by ultration. The concentrated culture broth was applied to a DEAE Sephadex A-50 column, and proteins were eluted stepwise with increasing concentrations of KCI. Fractions column. The molecty weight of purified toxin was39 kDa on SDS-PAGE, and Fourier tranformed infrared (FTIR) spectroscopy indicated that this toxin could be a new protein exhiting the charactristics of C=O stretching peak near 1650cm-1.