• Korean Journal of Food Science and Technology
• /
• v.30 no.3
• /
• pp.630-637
• /
• 1998

Enzymatic properties of immobilized transglucosidase (TG) from Aspergillus niger was characterized and compared with soluble TG. Michaelis-Menten constant $(K_m)$ and maximum velocity $(V_{max})$ of immobilized TG were $122\;mM,\;3.9{\times}10^{-2}\;mM/min$ and in case of soluble TG, 21 mM, 0.4 mM/min. The optimum pH of immobilized TG was pH 5.0 like soluble TG but immobilized TG showed 16% and 45% higher activity than soluble TG at pH 5.0 and pH 6.0. Both of immobilized TG and soluble TG were stable from pH 2.0 to pH 9.0, and therefore their activities in these pH ranges were remained more than 90%. The temperature was optimal at $60{\sim}70^{\circ}C\;and\;70{\sim}80^{\circ}C$ for soluble TG and immobilized TG, respectively. The thermal stability of immobilized TG was significantly improved than that of soluble TG, and immobilized TG retained $32{\sim}40%$ higher activity than soluble TG. D-values from thermal inactivation of immobilized TG were 7690 sec at $65^{\circ}C$, 83 sec at $75^{\circ}C$, 7.2 sec at $80^{\circ}C$. Z-values of soluble and immobilized TG were $6.4^{\circ}C\;and\;5.3^{\circ}C$, respectively. The little difference of activation energies of soluble TG and immobilized TG supposed that there was little difference in mass transfer limitation during the reaction of soluble TG and immobilized TG.

• Preventive Nutrition and Food Science
• /
• v.2 no.4
• /
• pp.281-284
• /
• 1997

Heat-induced gelation is an important functional property of whey proteins. Preheating of calcium reduced whey was reported to increase gel strength. 5% whey-protein solutions were preheated at pH7 and at various temperatures(60~8$0^{\circ}C$) for 15 minutes. The amount of soluble aggregates and denaturation enthalpy of preheated whey proteins were measured. Preheating temperature was negatively correlated with denaturation enthalpy($R^2$=0.857, P=0.08) and positive with the amount of soluble aggregates($R^2$=0.921, P=0.002). Denaturation enthalpy was negatively correlated with gel strength($R^2$=0.93, P=0.002). Soluble aggregates and gel strength were positively correlated($R^2$=0.972, P=0.0003). The formation of three dimensional gel network requires controlled protein denaturation and aggregation. Since preheating leads to the partial denaturation of proteins and the formation of soluble aggregates, preheated whey proteins have a higher gel strength than non-preheated one.

• Korean journal of food and cookery science
• /
• v.16 no.5
• /
• pp.390-393
• /
• 2000

Desmutagenic effects of water-soluble and ethanol-soluble extracts of dried green tea toward the mutagenicity of 4-nitroquinoline-N-oxide(4-NQO) and 3-Amino-1,4-dimethyl-5H-pyrido［4,3-b］indole(Trp-P-1) in streptomycin-dependent SD510 strains of Salmonella typhimurium TA98 were investigated. Inhibition effects toward the mutagenicity of 4-NQO and Trp-P-1 of water-soluble and ethanol-soluble extracts from green tea were high as increase of concentration of extracts. Desmutagenic effects toward 4-NQO of water-soluble and ethanol-soluble extracts from green tea harvested in May and August were up to 93% in 1,000 $\mu\textrm{g}$ of extract/plate. Desmutagenic effects toward Trp-P-1 of ethanol-soluble extracts from green tea were 53.3∼92.1%, but the effects of water-soluble extracts decreased as increase of concentration of extracts.

• IMMUNE NETWORK
• /
• v.13 no.4
• /
• pp.148-156
• /
• 2013

The $PrP^C$ is expressed in many types of immune cells including monocytes and macrophages, however, its function in immune regulation remains to be elucidated. In the present study, we examined a role for $PrP^C$ in regulation of monocyte function. Specifically, the effect of a soluble form of $PrP^C$ was studied in human monocytes. A recombinant fusion protein of soluble human $PrP^C$ fused with the Fc portion of human IgG1 (designated as soluble $PrP^C$-Fc) bound to the cell surface of monocytes, induced differentiation to macrophage-like cells, and enhanced adherence and phagocytic activity. In addition, soluble $PrP^C$-Fc stimulated monocytes to produce pro-inflammatory cytokines such as $TNF-{\alpha}$, $IL-1{\beta}$, and IL-6. Both ERK and $NF-{\kappa}B$ signaling pathways were activated in soluble $PrP^C$-treated monocytes, and inhibitors of either pathway abrogated monocyte adherence and cytokine production. Taken together, we conclude that soluble $PrP^C$-Fc enhanced adherence, phagocytosis, and cytokine production of monocytes via activation of the ERK and $NF-{\kappa}B$ signaling pathways.

• Korean Journal of Soil Science and Fertilizer
• /
• v.15 no.3
• /
• pp.162-165
• /
• 1982

As an approach to the explanation of increased availability of phosphate in reduced wetland soils, the interrelationships among pH, pe, $Fe^{+{+}}$ and water soluble phosphate in reduced soil-water suspension was studied. 1. p.e value of soil incubated for 8 weeks at $30^{\circ}C$ under waterlogged condition was sufficiently low to allow the conversion of strengite to vivianite. 2. The concentration of water soluble $Fe^{+{+}}$ in this system was higher than that is allowable by the solubility of vivianite. 3. From the relationship between pH and the concentration of water soluble $Fe^{+{+}}$, the concentration of water soluble $Fe^{+{+}}$ could be determined with the solubility of $FeCO_3$. 4. No definite relationship between pH and water soluble P was recognized which implied that the concentration of water soluble P in this system could not determined with the solubility of vivianite.

• The Korean Journal of Food And Nutrition
• /
• v.18 no.1
• /
• pp.4-10
• /
• 2005

Periodate-oxidized soluble starch increased pH stability of Aspergillus awamori a-glucosidase. After incubation for two hours, the enzyme in the absence of oxidized soluble starch was stable in the range of pH 3-7 at 40℃, pH 3-6 at 50℃ and the enzyme in the presence of oxidized soluble starch was stable in the range of pH 3-9 at 40℃, pH 3-8 at 50℃. At 60℃, the enzyme was stable in pH 3-6 regardless of the presence or absence of IO₄-oxidized soluble starch, but when IO₄-oxidized soluble starch existed in pH 5-6, remained activity of the enzyme increased 20% more than when it didn't exist. The enzyme modified with IO₄-oxidized soluble starch remained 70% of activity in pH 9, but native enzyme didn't remain, showing the increase of stability due to modification. In thermal stability, modified enzyme remained 12% at 50℃ and 7% at 80℃. But native enzyme remained 8% at 50℃ and didn't remain at more than 70℃. The result of HPLC analysis revealed the subunit of the enzyme at under pH 2 or over pH 9 was separated or the enzyme was denatured and conjugated. Protein structure of native enzyme was denatured by acidic and basic pH but was stable in the presence of IO₄-oxidized soluble starch.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.3 no.2
• /
• pp.67-70
• /
• 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.

• Korean Journal of Soil Science and Fertilizer
• /
• v.47 no.6
• /
• pp.563-570
• /
• 2014

The shortage or surplus of minerals directly affects overall physiological metabolism of plants; especially, it strongly influences carbohydrate metabolism as a primary response. We have studied mineral uptake, synthesis and partitioning of soluble carbohydrates, and the relationship between them in N, P or K-excessive tomato plants, and examined the interaction between soluble carbohydrates and mineral elements. Four-weeks-old tomato plants were grown in a hydroponic growth container adjusted with excessive N ($20.0mmol\;L^{-1}$ $Ca(NO_3)2{\cdot}4H_2O$ and $20.0mmol\;L^{-1}$ $KNO_3$), P ($2.0mmol\;L^{-1}$ $KH_2PO_4$), and K ($20.0mmol\;L^{-1}$ $KNO_3$), respectively, for 30 days. Shoot growth rates were significantly influenced by excessive N or K, but not by excessive P. The concentrations of water soluble N (nitrate and ammonium), P and K were clearly different with each tissue of tomato plants as well as the mineral conditions. The NPK accumulation in all treatments was as follows; fully expanded leaves (48%) > stem (19%) = roots (16%) = petioles (15%) > emerging leaves (1). K-excessive condition extremely contributed to a remarkable increase in the ratio, which ranged from 2.79 to 10.34, and particularly potassium was dominantly accumulated in petioles, stem and roots. Fresh weight-based soluble sugar concentration was the greatest in NPK-sufficient condition ($154.8mg\;g^{-1}$) and followed by K-excessive (141.6), N-excessive (129.2) and P-excessive (127.7); whereas starch was the highest in K-excessive ($167.0mg\;g^{-1}$) and followed by P-excessive (146.1), NPK-sufficient (138.2) and N-excessive (109.7). Soluble sugar showed positive correlation with dry weight-based total N content (p<0.01) whereas was negatively correlated with soluble P (p<0.01) and dry weight-based total P (p<0.01). On the other hand, starch production was negatively influenced by total N (p<0.001), but, it showed positive relation with total K concentration (p<0.05). This study shows that uptake pattern of NPK and production and partitioning of soluble carbohydrate were substantially different from each mineral, and the relationship between water soluble- and dry weight-based-mineral was positive.

• Journal of Environmental Health Sciences
• /
• v.17 no.1
• /
• pp.1-12
• /
• 1991

The atmospheric SO$_{2}$ concentrations and water soluble sulfur contents in Ginkgo biloba were measured and analyzed in auto-measuring station, Kwangleung, and Yongmun from August 5 to October 21, 1990. The results of the study are as follows: 1. Atmospheric SO$_{2}$ concentrations between the seoul area(Pulkwang, Ssangmun, Myonmok, Oilurn) in which the concentrations exceeded the air quality standards and the surburb of seoul (Kwangleung, Yongmun) revealed the significant difference (p<0.01). 2. Water soluble sulfur contents in Ginkgo biloba in autumn were higher than those in Ginkgo biloba in summer (p<0.01). Water soluble sulfur contents in leaves showed a significant difference between seoul and its surburb(p<0.01). 3. Correlation between atmospheric SO$_{2}$ concentration and water soluble sulfur content of Ginkgo biloba in autumn was as follow Y=0.2714+9.8123 X, r=0.6362 (X: Airborne SO${_2}$ Concentration according to sampling location, Y: Water Soluble Sulfur Contents)

• The Korean Journal of Ecology
• /
• v.16 no.1
• /
• pp.27-37
• /
• 1993

During the autumn of 1991, the water soluble sulfur content in litters of platanus orientalis on the street sides in seoul, pusan, taegu, taejeon, kwangji, ulsan and ch'unch'on cities were determined. The relationship between the water soluble s content in litters of p. orientalis and the traffic was analysed. The average content of water soluble s in litters of p. orientalis in pusan, taegu, taejeon, seoul, ulsan, ch'unch'on and kwangju cities were 0.71%, 0.60%, 0.66%, 0.58%, 0.50%, 0.43%, 0.38%, respectively. The correlation was not statistically significant between the s content in litters of p. orientalis is related to the traffic of each studied area. consequently the water soluble s content in litters of p. orientalis is supposed to be an indirect indicator of air pollution.