• Journal of the Korean Society of Radiology
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• v.9 no.7
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• pp.509-513
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• 2015

In this study, we evaluated the thermal denaturation characteristics of reusable NIPAM tissue mimicking (TM) Phantom by measuring the thermal sensitivity. And the changes of acoustic characteristic and thermal denaturation shape in NIPAM TM phantom according to the number of re-use time and re-use period were observed. With the result, as the sonication time is increased, the sound velocity of NIPAM phantom was decreased by 100 m/s and the attenuation was increased slightly. However, the changes according to the re-use period was not observed. In the thermal denaturation shape and size observation by ultrasound sonicaton, the remarkable changes have not been confirmed. With the result of this study, NIPAM Phantom was considered appropriate to evaluate and predict the effect of therapeutic ultrasound by in repeated sonication test.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.627-632
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• 1991

The heat treatment indicators such as HMF contents, lactulose contents and whey protein denaturation rates were measured to refer to the heat treatment intensity of domestic market infant formulae. The HMF contents showed $21.0{\sim}43.9{\mu}mol/l:$ in the case of powder types, the HMF contents in enriched nutrient products(ii) were higher whereas in the case of liquid types they were packed in cans(i). The lactulose contents showed $2.5{\sim}11.4mg/100ml$ in the powder type and $27.0{\sim}164.8mg/100ml$ in the liquid type. There was much difference in the lactulose contents according to the product types. Compared with the ADPI standards, most of infant formulae were considered to be medium-heat class. The whey protein denaturation rates were $1.1{\sim}69.4%$ in the powder type and $37.4{\sim}71.3%$ in the liquid type.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.81-85
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• 1970

In this studies, we isolated a kind of protein from Alisma Canaliculatum by the saline extraction. This protein was found to have a strong protective effects on the denaturation of ${\alpha}-chymotrypsin$ in the solution state. The obtained important results during the studies were as follows, 1. This protein was never hydrolyzed by the ${\alpha}-chymotrypsin$. 2. The denaturation of ${\alpha}-chymotrypsin$ was strongly protected by this sample protein. 3. Isoelectric point of this sample was about 4.7. 4. This sample protein was determined as an antigen but very weak antigenicity was indicated on rabbit.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.1
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• pp.33-37
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• 2004

In order to study the effect of temperature of denaturation, annealing and extension and cycles on amplification of DNA by PCR method, We isolated the hepatitis B virus DNA from hepatitis B patient blood and compared the density of DNA amplified by Reference PCR Program (denaturation at $94^{\circ}C$ for 30 sec., annealing at $60^{\circ}C$ for 1 min., extension at $72^{\circ}C$ for 1 min., holding at $72^{\circ}C$ for 5min., 30 cycles) that is usually used in laboratory to the density of DNA amplified by PCR program changed only the denaturation temperature or annealing temperature or extension temperature. We amplified about 341bp of hepatitis B virus DNA by Reference PCR Program from hepatitis patient blood, but the DNAs denatured at $72^{\circ}C$ or $60^{\circ}C$ were not detectable on photoradiography film. The DNA amplified at $37^{\circ}C$ of annealing temperature was not detectable, but the DNA annealed at $72^{\circ}C$ was detectable the lower density of DNA than the DNA amplified by Reference PCR Program. Each DNA amplified by PCR program changed only the extension temperature to $37^{\circ}C$ or $60^{\circ}C$ was almost same density as DNA amplified by Reference PCR Program. We compared the density of hepatitis B virus DNA amplified by Reference PCR Program for 30 cycles, 20 cycles, 10 cycles, and 5 cycles. The DNA cycled for 20 cycles was not amplified well as cycled for 30 cycles, but the DNA was detectable on the photoradiography film. The DNAs amplified for 10 cycles or 5 cycles were not detectable on photoradiorgaphy film. The concentration of hepatitis B virus DNA amplified in Reference PCR condition for 30 cycles, 20 cycles, 10 cycles, and 5 cycles were $72{\mu}g/m{\ell}$, $83{\times}10^{-3}{\mu}g/m{\ell}$, $27{\times}10^{-6}{\mu}g/m{\ell}$, and nondetectable, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.340-344
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• 1991

On heating and fleering food-stuffs, it is very important to obtain informations about thermophysical properties of fishes for designing of freezing and heating equipment and analyzing of physico-chemical reaction during storage. It is particularly necessary to measure denaturation enthalpy, temperature, latent heat of freezing, activation energy, enthalpy, entropy and free energy on freezing and heating rate. In this study, DSC was used to study effects of freezing and heating rate on thermophysical properties and denaturation temperature on scanning rate $2.5-10.0^{\circ}C/min$. On increasing scanning rate, denaturation temperature of protein and lipid incresed and freezing point, activation energy, enthalpy, entropy were decreased. In freezing process free energy of fishes were found to be $14.2-18.9 kcal/mol$.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.433-444
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• 1996

We describe a novel approach to evaluate quantitatively the amounts of denatured proteins in cells upon heat exposure. A thiol compound, diamide [azodicarboxylic acid bis (dimethylamide)] causes protein cross-linking with exposed sulfyhydryl residues of denatured proteins. Since denatured proteins expose normally well-hidden sulfhydryl groups, these will be preferentially cross-linked by diamide. Thus diamide acts to 'trap' denatured proteins. We observed that protein aggregates (high molecular weight protein aggregates, HMA) appeared on SDS-polyacrylamide gels run under non-reducing conditions and that the amount of HMA can be quantified by scanning the gels using a gas flow counter. Heating cells followed by a fixed dose of diamide exposure resulted in HMA increases in a heat-dose dependent manner, demonstrating that the quantitation of HMA could serve as a measure of heat-denatured proteins. We compared thermotolerant and nontolerant cells and found decreased HMA in tolerant cells upon heat treatment. As an attempt to examine the kinetics of protein renaturation (or 'repair'), we measured the amounts of aggregates formed by the addition of diamide at various times after heat shock. Such experiments demonstrate an equally rapid disappearance of HMA in previously unheated and in thermotolerant cells. Levels of HMA in tolerant cells increased significantly after electroporation of HSP70 specific mAbs, suggesting an involvement of HSP70 in reducing HMA levels in thermotolerant cells upon heat exposure. Immunoprecipitation studies using anti-HSP70 antibody indicated an association of HSP70 with heat-denatured proteins. Our results suggest that heat induces protein denaturation, and that elevated level of HSP70 present in thermotolerant cells protects them by reducing the level of protein denaturation rather than by facilitating the 'repair' (or degradation) process.

• Archives of Pharmacal Research
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• v.22 no.5
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• pp.485-490
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• 1999

The mechanism of action of fish oil (FO), currently used in different chronic inflammatory conditions such as rheumatoid arthritis (RA), is not completely understood, although it is thought that it could alter the metabolism of endogenous autacoids. In addition, we hypothesized that the known capability of fatty acids (FA) of stabilizing serum albumin and perhaps other proteins, may be of pharmacological relevance considering that it is shared by other anti-rheumatic agents (e.g. nonsteroidal antiinflammatory drugs). Thus, we studied the effect of oral administration of FO and corn oil (CO), a vegetable oil with a different composition, on the stability of rat serum proteins, evaluated buy a classical in vitro method based on heat-induced protein denaturation. FO, and, to a lower extent, CO inhibited heat-induced denaturation of rat serum (RS): based on the inhibitory activity (EC50) of the major fatty acids against heat-induced denaturation of RS in vitro, it was possible to speculate the in vivo effects of palmitic acid (C16:0) and eicosapentaenoic acid (EPA, C20:5, n-3) may be more relevant than that of linolenic acid (C18:2). To better investigate this phenomenon, we extracted albumin from the serum of animals treated or not with FO with a one-step affinity chromatography technique, obtaining high purity rat serum albumin preparations (RSA-CTRL and RSA-FO), as judged by SDS-PAGE with Coomassie blue staining. When these RSA preparations were heated at $70^{\circ}C$ for 30 min, it was noted that RSA-FO was much more stable than RSA-CTRL, presumably due to higher number of long chain fatty acids (FA) such as palmitic acid or EPA. In conclusion, we provided evidences that oral administration of FO in the rat stabilizes serum albumin, due to an increase in the number of protein bound long chain fatty acids (e.g. palitic acid and EPA). We speculate that the stabilization of serum albumin and perhaps other proteins could prevent changes of antigenicity due to protein denaturation and glycosylation, which may trigger pathological autoimmune responses, suggesting that this action may be involved in the mode of action of FO in RA and other chronic inflammatory diseases.

• Food Science of Animal Resources
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• v.22 no.2
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• pp.179-182
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• 2002

Using differential scanning calorimetry (DSC), changes underwent by a mixture of $\alpha$-lactalbumin ($\alpha$-La) and $\beta$-lactoglobulin ($\beta$-Lg) during heat treatment were studied, yielding useful information for the dairy industry. Results of the DSC showed that the heat denaturation temperature of the hobo-$\alpha$-La was higher than that of apo-$\alpha$-La, suggesting hole-$\alpha$-La‘s greater stability. The denaturation temperature of a mixture of holo-$\alpha$-La and $\beta$-Lg was also slightly lower than that of holo-$\alpha$-La alone. The denaturation temperature of an apo-$\alpha$-La and $\beta$-Lg mixture was higher than that of holo-$\alpha$-La and $\beta$-Lg, suggesting that the heat stability of apo-$\alpha$-La was increased by $\beta$-Lg. Based on these results, it is possible to conclude that a mixture of holo-$\alpha$-La and $\beta$-Lg is more intensively affected by an increase in temperature than other samples, and that free sulphydryl groups seem to take part in this heat-induced denaturation.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.43-49
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• 2008

Purpose: The current study was conducted to evaluate the compatibility of UV-A blocking contact lens on eye protection with regular contact lens. Methods: The protective activity of regular contact lens (UV-A blocking: 20%) and UV-A blocking contact lens (UV-A blocking: 85%) on the denaturation of RNase A, catalase, and superoxide dismutase (SOD) induced UV-A irradiation were compared by acrylamide gel electrophoresis. The enzyme solutions were irradiated with UV-A for 1, 3, 6, 24 and 96 hours at the wavelength of 365 nm. Covering area with contact lenses were varied as 50%, 70% and 100% according to the calculation of blocking areas of anterior eye that could be covered with RGP lens, soft contact lens, and eye glasses, respectively. Results: Denaturations of RNase, catalase and SOD were exaggerated when they were exposed to UV-A for a longer period. The denaturation was effectively prevented by UV-A blocking contact lens compared to regular contact lens. The capability of UV-A blocking contact lens was considerably reduced when the covering area with contact lens decreased and exposure time to UV-A extended. Conclusion: Therefore, it would be suggested that wearing contact lens for a long time under sunlight is carefully considered since the activity of UV-A blocking contact lens against UV-A irradiation may not be enough to protect enzymes presented in eyes when exposure time to UV-A increased.

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.270.1-270.1
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• 2000