• Biotechnology and Bioprocess Engineering:BBE
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• 제8권2호
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• pp.59-63
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• 2003

The protein disulfide isomerase (PDI) reaction kinetics has been studied to evaluate its effect on the monoclonal antibody (Mab) refolding and assembly which accompanies disulfide bend formation. The MAb in vitro assembly experiments showed that the assembly rate of heavy and light chains can be greatly enhanced in the presence of PDI as compared to the rate of assembly obtained by the air-oxidation. The reassembly patterns of MAb in-termediates were identical for both with and without PDI, suggesting that the PDI does not determine the MAb assembly pathway, but rather facilitates the rate of MAb assembly by promoting PDI catalyzed disulfide bond formation. The effect of growth rate on PDI activities for MAb production has also been examined by using continuous culture system. The specific MAb productivity of hybridoma cells decreased as the growth rate increased. However, PDI activities were nearly constant fur a wide range of growth rates except very high growth rate, indicating that no direct correlation between PDI activity and specific MAb productivity exists.

• 한국산학기술학회논문지
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• 제8권5호
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• pp.1273-1278
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• 2007

생체내에 존재하는 효소 등의 단백질은 그 골격을 이루는 아미노산 이외에 다양한 형태로 금속 원소들과 킬레이션을 이루고, 고유한 생리활성을 나타낸다. 단백질과 금속과의 킬레이션을 체계적으로 연구하기 위하여 가수분해하여 얻은 펩타이드와 Zn(II) 이온을 반응시키고, MALDI-TOF 질량분석기로 킬레이트 반응전 후의 펩타이드의 분자량을 측정하여 킬레이트 반응 생성물을 확인하는 분석법을 개발하고자 한다.

• 생명과학회지
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• 제7권4호
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• pp.322-328
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• 1997

Two phosphorylated proteins having molecular weights of 57kD and 72kD were detected from the slubilized membrane protein fraction of mating type a cells of Rhodosporidium toruloides which belongs to heterobasidiomycetous yeast. The phosphorylation of the protein was inhibited by a sexual pheromone, Rhodotorucine A (Rh. A), which is secreted from mating type a cells. On the other hand, counterpart mating type A cells and M-39 strain which is a styerile mutant derived from a cells, had also the same two phosphorylated proteins, However, the phosphorylation of the protein from A cells, and M-39 strain were not inhibited by the Rh. A. It suggests that inhibition of the phosphorylation reaction by the Rh. A in mating type a cells is a mating-type-specific reaction that relate to transduction mechanism of sexual pheromone signaling.

• Journal of Photoscience
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• 제9권2호
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• pp.1-4
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• 2002

Hula-twist is a volume-conserving photoisomerization reaction mechanism postulated in 1985 to account for the rapid photoisomerization of the retinyl chromophore in rhodopsin. The requisite stereochemical consequence of simultaneous isomerization of a double bond and an adjacent single bond has recently been demonstrated in isomerization of pre-vitamin D in an organic glass and by many other examples of organic systems already reported in the literature This paper reports the consequence in applying the mechanism to the primary photochemical process of several photosensitive biopigments: bilirubin, photoactive yellow protein, bacteriorhodopsin and rhodopsin. It is shown that the anchored nature of the chromophores must first be taken into consideration.

• Journal of Ginseng Research
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• 제16권2호
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• pp.129-137
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• 1992

This study was carried out to investigate the localization of lipids and lipase activity with lipid staining and cytochemical technique in endosperm cells of Panax ginseng C.A. Meyer seed. In endosperm cells of indehiscent seed, protein bodies facing the umbiliform layer are different in electron density during the various degraded processes. Gradually, protein matrix near the cell wall was lysed and electron lucent inclusions appeared on umbiliform layer. The protein body with high electron density and the spherosome with low electron density were observed in endosperm cells. As a result of lipid staining, electron density of spherosome is more intense than those of the protein matrix within the protein body in endosperm cells of indehiscent seed. Free spherical spherosomes within the umbiliform layer have a high electron density. The spherical spherosomes were more electron densed and were uniform in comparison with the cytoplasmic proteinaceous granules in endosperm cells of seed with red seed coat. The major component of spherosome was determined to be lipid. Lipase activity occurs in the spherosome and near the endosperm cell wall facing the umbiliform layer. Cytochemical reaction products of lipase were observed in the spherosome membrane and in the inner regions of spherosome. After protein bodies were digested, lipase activities were observed in free spherosomes and near the cell wall of endosperm cells. Umbiliform layer composing of fibrillized wall and digested materials of the endosperm cell showed a little lipase reaction products.

• 농업과학연구
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• 제24권2호
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• pp.121-125
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• 1997

베트남으로부터 수집된 총 437 벼 지역종을 사용하여 총 종자 단백질을 분석하기 위하여 SDS-PAGE와 phenol 반응을 수행하였다. 세 가지 다른 형태의 glutelin a subunit이 검출되었다. 60kDa의 분자량인 wx 단백질 수준은 세 그룹으로 분리되었는데, 이는 non-glutelin, intermediate, 그리고 glutelin 전분 유형이다 종자 저장 단백질과 wx 단백질의 변이에 의한 실험결과 지역종은 7그룹으로 구분된다. Glutelin a subunit의 A와 B형의 빈도분포는 벼 지역종이 수집된 위도에 따라서 변하였다. 페놀 반응에 대한 지리학적인 구배가 검출되었다.

• 한국식품과학회지
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• 제33권6호
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• pp.769-773
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• 2001

두유에서 발생되는 비지와 대두의 일반성분과 단백질의 추출률을 비교하기 위해 시간, 온도, pH별로 분석하였고, 단백질 분자들 사이의 상호작용에 관여하는 물질 urea, SDS, 2-mercaptoethanol를 사용하여 비지단백질의 insolubilization mechamism을 조사하였다. 또한 enzyme modification으로 기능성을 향상시켜 식품소재로서의 이용 가능성에 대해 분석하였다. 비지와 대두는 각각 37.3%, 42.5%의 단백질을 함유하고 있으며 비지는 생산공정 증의 과도한 열처리에 의하여 극히 낮은 용해도를 나타냈다. 비지단백질의 낮은 용해도는 주로 disulfide bonding에 의한 cross linking에 기인하는 것으로 밝혀졌다. 비지단백질과 대두단백질은 pH 3, pH 4에서 가장 낮은 용해도를 보였다. Carbohydrase와 protease를 첨가하여 단백질의 추출츌을 비교한 결과는 비지와 대두는 carbohydrase에서 미세한 반응을 보여 단백질의 용해도에 큰 영향을 주지 못하였으나 여러 protease 가운데 Alcalase는 비지단백질의 용해도를 급격히 증가시켰다.

• Journal of Ginseng Research
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• 제13권2호
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• pp.158-164
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• 1989

인삼엽소병(leaf-burning disease) 원인과 light-harvesting chlorophyll-protein(LHCP) complex의 solar energy 분배능력과의 상호 연관성을 조사하기 위한 기초 연구로써 인삼 thylakoid의 chlorophyll-protein(CP) complex의 조성 및 특징을 조사하였다. 인삼의 CP-complex는 non-denaturing SDS-PAGE 방법에 의해 4개 bands로 분리되었으며 각 band는 Bassi와 Dunahay의 결과에 따라 CPI(PSI의 reaction center와 LHCP I antennae), CP I(PSI reaction center), LHCP II(LHCP II)의 oligoform), 그리고 LHCP II(PS II antennae; CP29, CP26)로 확인되었다. 인삼의 LHCP II 는 양지식물인 spinach, soybean과 비교해 볼 때 오히려 인삼의 band intensity가 더 높았으며, CP I band는 인삼에서만 분리되었다. 인삼 CP-complex band의 absorption 및 fluorescence spectra, chlorophyll a.b ratio 에서도 비교식물과 차이를 나타내었다. Thylakoid membrane의 polypeptide 함량은 인삼에서 비교식물에 비해 현저히 낮은 polypeptide 함량은을 나타내었다. SDS-PAGE에 의한 polypeptide pattern은 band의 수나 band intensity에서 비교식물과 차이를 나타내었으며, 특히 29-35 kD, 55 kD과 60 kD 근치에서 현저한 band intensity 차이를 확인하였다. Specific $^1O_2$에 의해 chl. a가 60%, chl.b는 90%, 그리고 carotenoid는 70%가 파괴되는 것으로 확인되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제21권2호
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• pp.181-189
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• 2008

The aim of this study was to evaluate the effects of $Ca^{2+}$, $HCO_3{^-}$ and BSA on the in vitro capacitation-associated protein tyrosine phosphorylation, hyperactivation and acrosome reaction in guinea pig sperm. Caudal epididymal sperm were incubated in four different groups: modified TALP (Tyrode's albumin lactate pyruvate) or TALP without one of the medium constituents ($Ca^{2+}$, $HCO_3{^-}$ and BSA). After incubation for the required time (0 h, 0.5 h, 1 h, 3 h, 5 h, and 7 h), sperm were removed for further experiment. The capacitation effect was assessed by CTC (Chlortetracycline) staining. Western blotting and indirect immunofluorescence were used to analyze the level and localization of tyrosine phosphorylation. The results showed that guinea pig sperm underwent a time-dependent increase in protein tyrosine phosphorylation during the in vitro capacitation and the percentage of protein tyrosine phosphorylated sperm increased from 36% to 92% from the beginning of incubation to 7 h incubation. Also, there was a shift in the site of phosphotyrosine-specific fluorescence from the head of sperm to both the head and the flagellum. Moreover, an absence of $Ca^{2+}$ or $HCO_3{^-}$ inhibited in vitro hyperactivation and acrosome reaction and decreased the phosphorylation of the proteins throughout the period of in vitro capacitation. However, an absence of BSA could not influence these processes if substituted by polyvinyl alcohol (PVA) in the medium.

• Journal of Chest Surgery
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• 제51권3호
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• pp.187-194
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• 2018

Background: Death domain-associated protein (DAXX), originally identified as a pro-apoptotic protein, is now understood to be either a pro-apoptotic or an anti-apoptotic factor with a chromatin remodeler, depending on the cell type and context. This study evaluated DAXX expression and its clinical implications in squamous cell carcinoma of the esophagus. Methods: Paraffin-embedded tissues from 60 cases of esophageal squamous carcinoma were analyzed immunohistochemically. An immune reaction with more than 10% of tumor cells was interpreted as positive. Positive reactions were sorted into 2 groups: reactions in 11%-50% of tumor cells and reactions in more than 51% of tumor cells, and the correlations between expression and survival and clinical prognosticators were analyzed. Results: Forty-three of the 60 cases (71.7%) showed strong nuclear DAXX expression, among which 19 cases showed a positive reaction (31.7%) in 11%-50% of tumor cells, and 24 cases (40.0%) showed a positive reaction in more than 51% of tumor cells. A negative reaction was found in 17 cases (28.3%). These patterns of immunostaining were significantly associated with the N stage (p=0.005) and American Joint Committee on Cancer stage (p=0.001), but overall survival showed no significant difference. There were no correlations of DAXX expression with age, gender, or T stage. However, in stage IIB (p=0.046) and stage IV (p=0.014) disease, DAXX expression was significantly correlated with survival. Conclusion: This investigation found upregulation of DAXX in esophageal cancer, with a 71.7% expression rate. DAXX immunostaining could be used in clinical practice to predict aggressive tumors with lymph node metastasis in advanced-stage disease, especially in stages IIB and IV.