• Biotechnology and Bioprocess Engineering:BBE
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• 제3권2호
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• pp.67-70
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• 1998

In order to understand the influence of ferroxidase center on the protein assembly and solubility of tadpole ferrin, three mutant plasmids, pTH58K, pTH61G, and pTHKG were constructed with the aid of site-directed mutagenesis and mutant proteins were produced in Eshcerichia coli. Mutant ferritin H-subunits produced by the cells carrying plasmids pTH58K and pTHKG were active soluble proteins, whereas the mutant obtained from the plasmid pTH61G was soluble only under osmotic stress in the presence obtained from the plasmid pTH61G was soluble only under osmotic stress in the presence of sorbitol and betaine. Especially, the cells carrying pTH61G together with the plasmid pGroESL harboring the molecular chaperone genes produced soluble ferritin. The mutant ferritin H-subunits were all assembled into ferritin-like holoproteins. These mutant ferritns were capable of forming stable iron cores, which means the mutants are able to accumulate iron with such modified ferroxidase sites. Further functional analysis was also made on the individual amino acid residues of ferroxidase center.

• Journal of Pharmaceutical Investigation
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• 제28권2호
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• pp.121-126
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• 1998

The solubility and physicochemical stability of caroverine hydrochloride (CRV), an antispasmodic, in buffered aqueous solutions were studied using a reverse phase high performance liquid chromatography. The solubilty of the drug at pH 2.76-5.40 was similar at the range 31.9-36.2 mg/ml $(34^{circ}C)$, but, at the pH higher than 6.0, markedly decreased. The use of polyethylene glycol 400 as a cosolvent did not increase the solubility at any compositions examined. Moreover. increasing molar concentration of aqueous phosphate buffer from 0 to 0.5 M remarkably decreased the solubility. The degradation of CRY followed the apparent first-order kinetics. The degradation was accelerated with decreasing pH and increasing storage temperature. The half-lives for the degradation of CRY (1.0 mg/ml) at pH 1.28. 4.01 and 5.93 $(45^{\circ}C)$ were 2.8, 31.4 and 124 hr. respectively. The pHs of incubated solutions were to some extent lowered perhaps due to the formation of acidic degradation products. The addition of disodium edetate (0.01%) to the CRY solution (pH 4.95) retarded 2.5 times the degradation rate at $45^{\circ}C$, but the use of sodium bisulfite (0.1%) accelerated 2.9 times the rate. The activation energy for the CRY solution (20 mg/ml. pH 5.4) containing 0.01% EDTA was calculated to be 5.98 kcal/mole. When the solution was stored under nitrogen displacement in ampoule, there was no significant degradation even after 3 months at $40^{\circ}C$, indicating that protection from oxidation by air (oxygen) is essential for the complete stabilization of CRY solution.

• 한국식품조리과학회지
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• 제7권3호
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• pp.53-59
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• 1991

This study was carried out in order to investigate the change of protein functionalities such as foaming and emulsifying properties by succinylation of protein isolates. Succinylated and unsuccinylated munghean protein isolates were tested for finding out the effects of pH, heat treatment and sodium chloride concentration on the solubility, emulsion capacity, emulsion stability, foaming capacity, and foam stability. The results are summarized as follows: 1. Succinylation enhanced the solubility of MPI except at pH 4.5. When heated, succinylation greatly increased the solubility of succinylated MPI above $60^{\circ}C$. With the addition of NaCl, succinylation increased the solubility of MPI at acidic condition. 2. Emulsion capacity of succinylated MPI showed the lowest value at pH 7 and higher values at acidic and alkaine condition. when succinylated MPI was heated, emulsion capacity showed the highest at $80^{\circ}C$. With NaCl was added, emulsion capacity of succinylated MPI lincreased at pH 7, 9 or 11 decreased at pH 3 except addition of 1.0M NaCl. 3. Emulsion stability of MPI and succinylated MPI showed the highest at pH 4.5. Succinylation enhanced the emulsion stability of MPI at acidic condition. 4. The foaming capacity of MPI was increased at pH 3, 7 or 9 by succinylation. 5. When heated, foam stability of MPI and succinylated MPI showed the highest at pH 4.5 and at pH 11, respectively. When heated, both proteins showed the highest stability at $100^{\circ}C$.

• Nuclear Engineering and Technology
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• 제36권2호
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• pp.196-202
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• 2004

KAERI (Korea Atomic Energy Research Institute) is at present preparing a preliminary performance assessment to set up the HLW disposal concept of Korea. The solubility of the radionuclides contained in HLW is necessary as a source term in order to predict their potential migration in both the near and far fields. The solubility of actinides (Th, Am, U, Np and Pu) for a reference deep groundwater of Korea has been calculated using a geochemical code with thermodynamic data selected by a peer review of existing thermodynamic databases and literature. The solubilities from the experimental study and/or field observations from natural analogue studies are compared. The sensitivity of solubility to the variability of three main parameters of groundwater (pH, Eh, and carbonate concentration) is also investigated. The results of the sensitivity analysis show that the solubility of actinides strongly depends on the parameters considered. Within the range of parameter values studied (pH=7 to 10, Eh=-0.4 to -0.1V, and carbonate concentration=1.E-5 to 1.E-2 mol/L), the solubility of each actinide exists between 1.4E-10 and 1.6E-6 mol/L for Am, 4.9E-9 and 2.8E-6 mol/L for Th, 3.2E-9 and 5.7E-4 mol/L for U, 1.1E-9 and 1.0E-7 mol/L for Np, and 4.0E-11 and 2.8E-6 mol/L for Pu, respectively.

• 한국식품과학회지
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• 제31권3호
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• pp.658-664
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• 1999

GOD (glucose oxidase)나 제빵용 효모를 사용하여 포도당이 제거된 육계와 돼지 혈장분의 상온 저장중 색깔, biuret 단백질 함량, 용해도, 기포력과 pH의 변화를 조사하였다. 혈장분의 종류와 혈당 제거 법과는 상관없이 실험기간 동안 혈당이 제거된 혈장분은 해당 대조구보다 "L" 값이 같거나 높았으며 "a" 값과 "b"값은 낮았다(P<0.05). 축종 또는 혈당 제거 방법과는 상관없이 탈당된 모든 시료의 단백질 함량과 용해도는 상온 저장중 해당 대조구보다 항상 높았고 저장 기간이 경과할수록 감소하는 경향을 보였다(P<0.05). 대체적으로 탈당된 육계와 돼지 혈장분 기포력은 해당 대조구와 비슷하거나 높았다. 그러나 돼지 혈장분의 기포력은 육계 혈장분과는 다르게 실험기간 동안 탈당된 돼지 혈장분과 상응하는 대조구는 큰 차이를 나타내지 않았다(P<0.05). 육계 대조구와 GOD로 혈장 포도당을 제거한 육계 혈장분의 pH는 저장기간이 지남에 따라 감소하였지만 효모로 포도당을 제거한 육계 혈장분과 모든 돼지 시료의 pH는 실험 기간중 증가하였다가 감소하였다. GOD로 포도당을 제거한 육계 혈장분이 해당 육계 시료 보다 낮은 pH값을 보인 반면 돼지 혈장분에서는 대조구가 상응하는 실험구보다 항상 낮은 pH 값을 나타내었다(P<0.05). 육계와 돼지 혈장의 포도당을 제거한 후 혈장을 건조시키면 혈장분의 색깔, biuret 단백질 함량, 용해도 그리고 기포력을 증진시킬 수 있었다.

• 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.

• 약학회지
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• 제46권3호
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• pp.168-173
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• 2002

The physicochemical properties of aloesin, which has been recently found to reduce renal toxicity induced by cis-platin, were studied including solubility, partition coefficient ( $P_{c}$ ), osmolality, and stability. The solubility of aloesin was about 500 mg/mι, and the $P_{c}$ value for n-octanol/water was 1.01 $\pm$ 0.03. The degradation of aloesin followed the pseudo-first-order kinetics and was dependent on temperature, pH and ionic strength. From the pH-rate profile, the optimal pH was found to be 2.0~3.0. Some metal ions increased the degradation rate in the rank order of M $n^{2+}$ ＞ F $e^{3+}$ ＞ C $u^{2+}$ ＞ F $e^{2+}$. On the other hand, other metal ions such as B $i^{3+}$, $Ba^{2+}$, Z $n^{2+}$, N $i^{2+}$, $Co^{2+}$ and $Mg^{2+}$ did not show the unfavorable effects. After autoclaving, aloesin contents remaining were 81.8~98.8% of initial concentrations depending on pH. The most stable pH was 3.98 in the autoclaving. Osmolality increased linearly as concentration increased.sed.creased.sed.

• Restorative Dentistry and Endodontics
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• 제35권5호
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• pp.344-352
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• 2010

연구목적: 본 연구의 목적은 glass ionomer cement (GIC)와 혼합한 mineral trioxide aggregate (MTA)의 경화 시간, 압축 강도, 용해도, pH를 평가하고 이것을 MTA, GIC, IRM, SuperEBA와 비교하는 것이다. 연구 재료 및 방법: 경화 시간과 압축 강도는 ISO 9917, 그리고 용해도는 ISO 6876 기준에 따라 측정하였다. pH는 고체시편 전용 전극이 연결된 pH meter를 이용하여 측정하였다. 결과: GIC와 혼합한 MTA의 경화시간은 MTA보다 유의하게 짧았으며 압축 강도는 7일간 모든 시점에서 다른 재료보다 유의하게 낮았다. GIC와 혼합한 MTA 중에서 1 : 1과 2 : 1 시편의 용해도는 다른 실험군보다 유의하게 높았다. 또한 GIC와 혼합한 MTA의 pH는 혼합직후 2-4의 범위에서 1일 후 5-7 사이로 증가하였다. 결론: GIC와 혼합한 MTA의 경화시간은 MTA에 비해 개선되었으나 압축강도 및 pH와 같은 다른 성질들은 MTA에 비해 오히려 열등한 것으로 밝혀졌다. 임상적 사용이 가능하려면, MTA의 기존 장점을 저해하지 않으면서 단점을 개선하기 위한 적절한 혼합비를 찾아내고 생체친화성을 평가하는 추가적인 연구가 필수적이다.

• KSBB Journal
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• 제23권6호
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• pp.546-550
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• 2008

본 연구에서는 아스타잔틴의 각종 유기용매와 물에 대한 용해도와 산화, 빛, 온도 및 pH에 의한 아스타잔틴의 안정성을 검토하였다. 아스타잔틴은 유기용매인 아세톤과 아세트산에 비교적 용해도가 높았으며 물에는 거의 용해되지 않았다. 아스타잔틴의 용해도에 미치는 pH의 영향을 검토한 결과, 산성 조건 (pH 2)에서는 중성이나 염기성 조건에 비하여 용해도가 10-20배 증가하였다. 아스타잔틴은 산화와 빛에 대한 안정성이 매우 낮았으며, pH 3에서도 안정성이 급격히 떨어지는 것으로 조사되었다. 온도에 대한 영향을 조사한 결과, 상온 보관시에도 아스타잔틴이 쉽게 분해되었으며, 특히 $100^{\circ}C$에서 5초 동안 가열할 경우 아스타잔틴이 90% 이상 분해되었다. 결론적으로 아스타잔틴을 식품이나 화장품 등의 산업적 활용을 위해서는 안정성과 용해도 개선이 요구되는 것으로 판단되었다.

• Fisheries and Aquatic Sciences
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• 제24권12호
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• pp.406-414
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• 2021

The objective of this study was to investigate the yield and characteristics of collagen protein extracted from the muscle of four different species of mantis shrimp: Miyakella nepa, Harpiosquilla harpax, Erugosquilla woodmasoni, and Odontodactylus cultrifer. Mantis shrimp muscle was extracted by using a pepsin-solubilization technique, with 0.5 M acetic acid and 5% pepsin enzyme. The highest collagen yield was from M. nepa muscle (0.478 ± 0.06%), which was significantly greater (p < 0.05) than that from H. harpax, O. cultrifer, and E. woodmasoni (0.313 ± 0.03%, 0.123 ± 0.02%, and 0.015 ± 0.00%, respectively). The freeze-dried collagen appeared as thin fibers, and formed an opaque film. The pepsin-soluble collagen (PSC) from four mantis shrimp species was analyzed by gel electrophoresis. The results showed that all species of mantis shrimp contained type I collagen, consisting of β, α1, and α2 subunits with average molecular weights of 250, 145, and 118 kDa, respectively. The study of the solubility of collagen showed that, for NaCl, collagen had the highest relative solubility in 2% NaCl (80.20 ± 4.95%). In contrast, the solubility decreased at higher NaCl concentrations. However, in terms of pH, collagen had the highest relative solubility at pH 3 (91.32 ± 5.14%), and its solubility decreased at higher pH. FT-IR spectroscopy was used to compare the collagen with a model compound. Five wavenumbers in the spectrum for model collagen were identified: Amide A (3,406-3,421 cm^-1), amide B (2,916-2,940 cm^-1), amide I (1,639-1,640 cm^-1), amide II (1,539-1,570 cm^-1), and amide III (1,234-1,250 cm^-1).