• Journal of Applied Biological Chemistry
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• 제58권2호
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• pp.97-100
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• 2015

The thermostable pectinase gene TmPec isolated from Thermotoga maritima was introduced into the NdeI site of pRSET-B vector and expressed in its intact form in Escherichia coli BL21. The overexpressed intact form of pectinase (TmPecN protein) was partially purified by heat-denaturation procedure. TmPecN showed the highest activity between 85 and $95^{\circ}C$, and at approximately pH 6.5. Enzyme activity was stably maintained at temperatures below $85^{\circ}C$. In the presence of $Ca^{2+}$, pectinase activity of TmPecN increased to 128.4% of normal level. In contrast, $Ba^{2+}$, $Zn^{2+}$, and $Mn^{2+}$ strongly inhibited TmPecN activity. We conclude that the biochemical properties of the intact form of TmPecN are comparable to those of the recombinant protein TmPec reported previously.

• 한국식품영양학회지
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• 제10권2호
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• pp.160-165
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• 1997

오징어의 actomyosin과 myosin은 3$0^{\circ}C$에서 최대 Vmax를 나타냈고 대합의 actomyosin과 myosin은 35$^{\circ}C$에서, HMM은 $25^{\circ}C$에서 최대 Vmax를 보였다. 또한 근원섬유단백질의 열 안정성은 염농도의 차이에 따라 크게 변하여 염농도가 높을수록 변성의 정도가 컸으며 대합의 근원섬유단백질이 오징어의 근원섬유단백질보다 높은 열 안정성을 나타냈다. 근원섬유단백질에 3%의 에탄올을 첨가하여 가온하면 변성은 가속화되었으며 변성속도에 있어서도 동물간에 차이가 있는 것으로 나타났다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
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• pp.146-148
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• 2001

The objective of this study was to investigate the behavior of ribonuclease A (RNase) at the water/methylene chloride interface. It was aimed at better understanding the denaturation of proteins upon emulsification. RNase was vulnerable to the interface-induced aggregation reactions that led to formation of water-insoluble aggregates upon emulsification. Biochemical analyses demonstrated that intermolecular covalent linkages might have been involved in the aggregation reactions. The protein instability observed with emulsification was traced to consequences of protein adsorption and conformational rearrangements at the interface. These results indicated that emulsifying aqueous protein solutions in organic solvents should be handled with care, since emulsification could bring denaturation and aggregation to proteins.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2006년도 정기총회 및 제37차 춘계 국제학술발표대회
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• pp.94-97
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• 2006

Proteolytic enzymes and ginger extract were effective on tenderising M. pectoralis profundus, resulting in higher collagen solubility, a decrease of melting denaturation temperature and WBSF compared with the control. Comparing all treatments, bromelain treatment showed to be higher for collagen solubility than other treatments, but no significant differences in onset and melting denaturation temperature of intramuscular connective tissue were found. These corresponded to WBSF results. The present study indicates that ginger extract might be effectively able to be utilised in pilot level as better alternatives to bromelain and papain for tenderisation of tough meat, such as cull cow and beef cuts with many collagen.

• Korea-Australia Rheology Journal
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• 제19권2호
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• pp.81-88
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• 2007

Blends of collagen dispersion (COL) with poly(vinyl alcohol) (PVA) in different weight ratios were investigated by oscillatory rheometry, Fourier transform-infrared spectroscopy and scanning electron microscopy. It was found that even with 80% of PVA, the COL/PVA blends behaved more like collagen dispersion than pure PVA solution in the dynamic thermal and frequency processing, for instance, a dominant elastic appearance (G'>G"), a similar shear thinning behavior and the thermal denaturation below $40^{\circ}C$. However, influence on the blend behaviour by PVA was noticeable, for instance, an increase of dynamic denaturation temperature, the decreasing intensity of amide I, II and III bands as well as the diminishing irregular pores on the surface of blends. The interaction between collagen and PVA could be observed, especially at the regions with low content or high content of PVA.

• 한국축산식품학회지
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• 제18권4호
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• pp.358-363
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• 1998

The objectives of this study were to evaluate the effect of previous heating temperature and holding times on the thermal behavior of pork loin muscle by DSC. Pork loin muscles were heated to achieve the following end-point temperatures: 40$^{\circ}C$, 50$^{\circ}C$, 60$^{\circ}C$, 70$^{\circ}C$, 80$^{\circ}C$ at heating rate = 10$^{\circ}C$/min. The first peak was disappeared when samples were initially heated to 50$^{\circ}C$ for 1 minute. As end-point temperature was raised, major peaks were progressively disappeared and peaks were lost completely at 80$^{\circ}C$. Especially, peaks were completely disappeared at 70$^{\circ}C$ for 10 minute. Increasing of exposure time to elevated temperature also increased denaturation, thereby reducing the area of the thermogram.

• Food Science and Biotechnology
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• 제14권1호
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• pp.11-15
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• 2005

Dynamic shear moduli of isolated soy protein solutions upon heating were measured to monitor gelation. Onsets of gelation coincide with onset temperatures of denaturation in glycinin and ${\beta}$-conglycinin solutions, whereas in isolated soy proteins, onset of gelation was above denaturation temperature of ${\beta}$-conglycinin with storage modulus increasing in two steps. The first increase in storage modulus of isolated soy proteins occurred at about $78.5^{\circ}C$, while the second increase started at about $93^{\circ}C$. Gel properties of soy protein gels having different proportions of glycinin and ${\beta}$-conglycinin were measured by compression-decompression test. ${\beta}$-conglycinin was responsible for gel elasticity. Glycinin significantly increased hardness, toughness, and fracturability of gels at high heating temperature near $100^{\circ}C$. Results reveal texture of soy protein gels can be controlled by regulating ratio of glycinin to ${\beta}$-conglycinin and heating temperature.

• Bulletin of the Korean Chemical Society
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• 제29권1호
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• pp.208-210
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• 2008

• 한국미생물·생명공학회지
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• 제13권1호
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• pp.7-11
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• 1985

인삼(人蔘) saponin의 생물학적(生物學的) 활성(活性)을 조사(調査)하기 위하여 세균(細菌) v{\alpha}$-amylase의 작용(作用)에 미치는 인삼(人蔘) saponin의 영향(影響)을 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. Protopanaxadiol계(系), triol계(系) 및 total saponin 모두 ${\alpha}$-amylase의 활성(活性)을 25, 12, 13%정도(程度) 촉진(促進)시켰다. Diol계(系) saponin첨가(添加)경우 $40^{\circ}C$에서 3분간(分間) 전처리(前處理)함으로서 ${\alpha}$-amylase의 활성(活性)을 20%정도(程度) 촉진(促進)시켰으며 酵素(효소)의 열변성(熱變性)에 대(對)한 보호작용(保護作用)은 protopanaxariol계(系) saponin은 $60^{\circ}C$에서 5분(分)까지는 보호작용(保護作用)이 있었으나 protopanaxadiol계(系) saponin은 오히려 열실활(熱失活)을 촉진(促進)하는 경향이었다. Diol 및 triol계(系) saponin의 산가수분해물(酸加水分解物)이 ${\alpha}$-amylase의 활성(活性)을 diol 및 triol계(系) saponin보다 더 촉진(促進)시켰으며 diol, triol계(系) saponin의 첨가(添加)는 고농도(高濃度)의 기질(基質)이 존재(存在)할 때 기질저해(基質沮害)를 막아주었다.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2523-2528
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• 2014

In the present study, at first, azo Schiff base ligand of (N,N'-bis(5-phenylazosalicylaldehyde)-ethylenediamine) ($H_2L$) has been synthesized by condensation reaction of 5-phenylazosalicylaldehyde and ethylenediamine in 2:1 molar ratio, respectively. Then, its cobalt complex (CoL) was synthesized by reaction of $Co(OAc)_2{\cdot}4H_2O$ with ligand ($H_2L$) in 1:1 molar ratio in ethanol solvent. This ligand and its cobalt complex containing azo functional groups were characterized using elemental analysis, $^1H$-NMR, UV-vis and IR spectroscopies. Subsequently, the interaction between native calf thymus deoxyribonucleic acid (ct-DNA) and CoL complex was investigated in 10 mM Tris/HCl buffer solution, pH = 7 using UV-vis absorption, thermal denaturation technique and viscosity measurements. From spectrophotometric titration experiments, the binding constant of CoL complex with ct-DNA was found to be $(2.4{\pm}0.2){\times}10^4M^{-1}$. The thermodynamic parameters were calculated by van't Hoff equation.The enthalpy and entropy changes were $5753.94{\pm}172.66kcal/mol$ and $43.93{\pm}1.18cal/mol{\cdot}K$ at $25^{\circ}C$, respectively. Thermal denaturation experiments represent the increasing of melting temperature of ct-DNA (about $0.93^{\circ}C$) due to binding of CoL complex. The results indicate that the process is entropy-driven and suggest that hydrophobic interactions are the main driving force for the complex formation.