• Journal of Nutrition and Health
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• v.25 no.3
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• pp.256-263
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• 1992

As various metabolic alterations develope in uremic patients. their diets need to be restricted, Furthermore medical complications with accompanying anorexia result in further complications and decrease in body strength. To assess the nutritional status of hemodialyzed patients we performed evaluation for dietary intake and protein catabolic rate(PCR) For 24 clinically stable male patients undergoing maintenance hemodialysis dietary intake was estimated by 3-day food record method and PCR was calculated with blood urea nitrogen at pre and post hemodialysis. The results were as follows : 1) Average daily energy and protein intake were 26.7$\pm$5.1kcal/kg of body weight. 0.95$\pm$0.19 g/kg of body weight respectively. 2) Protein catabolic rate calculated from interdialysis blood urea nitrogen levels was 1.00$\pm$0.20g/kg of body weight. Protein catabolic rate was correlated with the amount of Protein intake(r=0.44 p<0.05) 3) Relative body weight(RBW) of the subjects was smaller than that of healthy man without hemodialysis. Calorie and protein intake and protein catabolic rate were significantly different (p<0.05) between patients with lower RBW(<90% of ideal body weight) and those with normal RBW(90~110% of ideal body weight) and those with normal RBW(90~110% of iedal body weight) 4) The duration of hemodialysis did not have a significant effect on the nutritional status of the subjects.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.504-508
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• 2003

In this study, development of papain which is extremely stable to negative ionic environment was made by directed molecular evolution. The screening method to confirm papain activity was designed using anionic material and skim milk agar plate for obtaining stable modified papain. Most stable modified papain P38-10 was obtained, which shows activity 10-15 times higher compared to wild type papain in anionic environment.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.1
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• pp.9-18
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• 2003

The most challenging and emerging field of biotechnology is the tailoring of proteins to attain the desired characteristic properties. In order to increase the stability of proteins and to study the function of proteins, the mechanism by which proteins fold and unfold should be known. It has been debated for a long time how exactly the linear form of a protein is converted into a stable 3-dimensional structure. The literature showed that many theories support the fact that protein folding E5 a Thermodynamically controlled process. It is also possible to predict the mechanism of protein deactivation and Stability to an extent from thermodynamic studies. This article reviewed various theories that have been proposed to explain the process of protein folding after its biosynthesis in ribosomes. The theories of the determination of the thermodynamic properties and the interpretation of thermodynamic data of protein stability are 3150 discussed in this article.

• Korean Chemical Engineering Research
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• v.58 no.2
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• pp.280-285
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• 2020

We have developed a constitutive display system of the Pseudomonas fluorescens SIK W1 TliA lipase on the cell surface of Escherichia coli using E. coli outer membrane protein C (OmpC) as an anchoring motif, which is an economical compared to induced system. For the constitutive expression of truncated OmpC-TliA fusion proteins, gntT104 promoter was employed. Cell growth was not affected by over expression of fusion protein during entire culture time, suggesting cell lysis was not a problem. The localization of truncated OmpC-TliA fusion protein on the cell surface was confirmed by immunofluorescence microscopy and measuring whole cell lipase activity. Constitutively displayed lipase was very stable, retaining activity enantioselectivity throughout the five repeated reactions. These results suggest that OmpC from E. coli be a useful anchoring motif for displaying enzymes on the cell surface without any inducers, and this stable surface display system can be employed for a broad range of biotechnological applications.

• BMB Reports
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• v.33 no.2
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• pp.155-161
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• 2000

The saccharomyces cerevisiae Rad27, a structure-specific endonuclease for the okazaski fragment maturation has been known to interact genetically and biochemically with Dna2, an essential enzyme for DNA replication. In an attempt to define the significance of the interaction between the two enzymes, we expressed and purified both Dna2 and Rad27 proteins. In this report, Rad27 could not form a complex with Dna2 in the three different analyses. The analyses included glycerol gradient sedimentation, protein-column chromatography, and coinfection of baculoviruses followed by affinity purification. This is in striking contrast to the previous results that used crude extracts. These results suggest that the interaction between the two proteins is not sufficiently stable or indirect, and thus requires an additional protein(s) in order for Rad27 and Dna2 to form a stable physical complex. This result is consistent with our genetic findings that Schizosaccharomyces pombe Dna2 is capable of interacting with several proteins that include two subunits of polymerase $\delta$, DNA ligase I, as well as Fen-1. In addition, we found that the N-terminal modification of Rad27 abolished its enzymatic activity. Thus, as suspected, we found that on the basis of the structure determination, N-terminal methionine indeed plays an important role in the nucleolytic cleavage reaction.

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.14-14
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• 1996

The metastable native state of proteins plays an important role in regulating biological functions. The native strain of serpins (serine protease inhibitors) are considered to be crucial for the inhibitory function. Several thermostable mutations of human $\alpha$$_1$-antitrypsin, a prototype inhibitory serpin, were identified in a systematic search targeted at the hydrophobic core of the molecule [Nature structural biology, vol. 3, no. 6, 497-500(1996)]. (omitted)

• Journal of Plant Biology
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• v.39 no.4
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• pp.301-307
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• 1996

The disassembly of Chl-protein complexes during dark-induced senescence (DIS) was investigated using detached third and fourthleaves of 21$\pm$1 day-old Arabidopsis thaliana. Although Chl content decreased linearly after 1 d, a significant decrease of photochemical effeciency (Fv/Fm) was observed after 2 d. In experiments using native green gel electrophoresis of Chl-protein complexes combined with additional two-dimensional SDS-PAGE analysis, we could observe the degradation of both photosystems after 2 d. Although light-harvesting complex(LHC) for PSI (LHCI) was degraded first in PSI complex, small PSII apoproteins including CP47/CP43 and D1/D2 apoproteins were degraded first in PSII complexes. LHC for PSII (LHCII) trimers were stable until 4 d. The level of LHCII monomers was increased until 3 and decreased thereafter, resulting in the increase of free pigments. These results suggest that the disassembly process of PSI is different from that of PSII.

• Archives of Pharmacal Research
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• v.16 no.1
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• pp.57-61
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• 1993

Based on the turbidimetric response of protein with 50% trichloroacetic acid (TCA), this study aims to introduce an assay method for protein in solution. The standard procedure consists of mixing equal volume of sample solution (standard or unknown) with 50%-TCA solution and measuring the absorbance at 450 nm after 20 min. The absorbances of the solutions were almost stable over 120 min at room temperature. This assy method is simple, reproducible, and tolerant to many interfering substances. It can detect less amount than $10\mu$g/ml of bovin serum albumin. The assay method has low protein-to-protein variability over wide range of molecular weight.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.610-617
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• 2009

The stability of corn oil-in-water emulsions coated by milk proteins, sodium caseinate (CAS), or whey protein concentrate (WPC), was compared under the environmental stress of pH change. Emulsions were prepared at 0.1 of protein:oil because the majority of droplets were relatively small ($d_{32}=0.34$ and $0.35\;{\mu}m$, $d_{43}=0.65$ and $0.37\;{\mu}m$ for CAS- and WPC-emulsions, respectively) and there was no evidence of depletion flocculation. As the pH of the emulsions was gradually dropped from 7 to 3, there was no significant difference in the electrical charges of the emulsion droplets between the 2 types of emulsions. However, laser diffraction measurements, microscopy measurements, and creaming stability test indicated that WPC-emulsions were more stable to droplet aggregation than CAS-emulsions under the same circumstance of pH change. It implies that factors other than electrostatic repulsion should contribute to the different magnitude of response to pH change.

• BMB Reports
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• v.41 no.5
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• pp.382-387
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• 2008

It is known that the stable protein 1 (SP1) detected in aspen plants remains soluble upon boiling and that sp1 expression in transgenic aspen is resistant to salt stress. Presently, we analyzed the effect of expression of SP1 in Arabidopsis thaliana plants and their response to high temperature stress. After $45^{\circ}C$ for 16 h, relative to wild type plants, sp1 transgenic plants exhibited stronger growth and were better in several physiological properties including chlorophyII, chlorophyII fluorescence, water content, proline content, and malondialdehyde content. These preliminarily results suggest that the over-expression of SP1 may notably enhance heat-tolerant level of transgenic A. thaliana plants.