• KSBB Journal
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• v.22 no.1
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• pp.48-52
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• 2007

This study was carried out to establish the optimum disruption condition of a sonificator for the protein toxin for the purpose of developing automatic biological agent detector equipped a sonificator. One of the best-known collisional quenchers is molecular oxygen, which quenches almost all known fluorophores. The sonification does an excellent job of degassing, which decreased the quenching effect and increased the fluorescence quantity. The fluorescence measurement for the protein using 0.7 X fluorescent dye concentration and above must be done in 1 minute and the fluorescence measurement for the protein using 0.3 X fluorescent dye concentration and below has to be done between 2 and 3 minute. The fluorescence quantity of the sonificatied protein sample was much higher that of the non-sonificatied protein sample. Sonificating the sample turned out to be favorable for the fluorescence measurement when measuring at the low protein concentration.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.252-255
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• 1999

Inhibition activities$(pI_{50})$ of chalcone derivatives as substrate with farnesyl protein transferase(FPTase) were determined in vitro. The structure activity relationships(SAR) between the activity and physicochemical parameters of X & Y-substituents on the phenyl groups were analyzed by Free-Wilson and Hansch method. X-substituents on the benzoyl group have the more important role to inhibition activity than Y-substituents on the styryl group. Among them, none substituent, 8 showed the highest FPTase inhibition activity$(pI_{50}=4.30)$. Particularly, the SAR equation could be formulated, showing a parabolic relationship between the activity and hydrophobicity(logP) where the optimal value$({\Sigma}logP)_{opt}$ was 3.915. And also the activity depends on the steric effect(Es > 0) with X-substituent and the resonance effect(R < 0) with electron donating Y-substituents. Based on the results of SAR analyses, the interactions between substrates and receptor, FPTase, could be assumed.

• Journal of Life Science
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• v.23 no.8
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• pp.978-983
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• 2013

Kinesin-II, a molecular motor, consists of two different motor subunits, KIF3A and KIF3B, and one large kinesin superfamily-associated protein 3 (KAP3), forming a heterotrimeric complex. KAP3 is associated with the tail domains of motor subunits. However, its exact role remains unclear. Here, we demonstrated KAP3 binding to the carboxyl (C)-terminal tail region of HS-associated protein X-1 (HAX-1). HAX-1 bound to the C-terminal region of KAP3, but not to KIFs (KIF3A, KIF3B, and KIF5B) and the kinesin light chain (KLC) in the yeast two-hybrid assays. The interaction was further confirmed in the glutathione S-transferase (GST) pull-down assay and by co-immunoprecipitation. Anti- HAX-1 antibody as well as anti-KIF3A antibody co-immunoprecipitated KIF3B and KAP3 from mouse brain extracts. These results suggest that KAP3 could mediate the interaction between Kinesin-II and HAX-1.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.784-788
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• 1995

The lambda Integrase (Int) carries out site-specific recombination between the two partner DNA sequences, attachment P (attP) and attachment B (attB). In order to study the recombination mechanism, a large quantity of pure integrase is required. Then, we constructed an int gene inserted recombinant plasmid (pNYL3) by using the pQE31 HIS-Tag vector, and produced the fusion protein, 6xHIS-Int from the E. coli TG1 strain carrying the pNYL3 plasmid. The recombinant protein produced was purified by phosphocellulose and Ni$^{++}$-NTA affinity column chromatographies. The result of the in vitro recombination assay using the standard reaction mixture containing 6xHIS-Int and partially purified integration host factor (IHF) showed that the 6xHIS-Int tagged recombination Integrase had the full recombination activity.

• BMB Reports
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• v.37 no.1
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• pp.28-34
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• 2004

The discovery of biochemical and cellular functions of unannotated gene products begins with a database search of proteins with structure/sequence homologues based on known genes. Very recently, a number of frontier groups in structural biology proposed a new paradigm to predict biological functions of an unknown protein on the basis of its three-dimensional structure on a genomic scale. Structural proteomics (genomics), a research area for structure-based functional discovery, aims to complete the protein-folding universe of all gene products in a cell. It would lead us to a complete understanding of a living organism from protein structure. Two major complementary experimental techniques, X-ray crystallography and NMR spectroscopy, combined with recently developed high throughput methods have played a central role in structural proteomics research; however, an integration of these methodologies together with comparative modeling and electron microscopy would speed up the goal for completing a full dictionary of protein folding space in the near future.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.633-638
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• 2007

This study was conducted to determine the protein requirement level in growing Jindo dog through nitrogen balance experiment. Twelve female dogs aged 18～20 weeks old were allotted one of 3 dietary treatments containing 21, 23 and 25% of crude protein. Average daily gain of dogs fed experimental diets containing 21, 23 and 25% of crude protein were 65.42, 79.58 and 99.17g/d, respectively, and there was a significant difference between 21 and 25% of crude protein treatments(p<0.05). Retained nitrogen were calculated 0.74, 0.96 and 1.31g/kgBW.75/d for dogs fed diets containing 21, 23 and 25% of crude protein, respectively, and were significantly higher(p<0.05) in dogs fed 25% of crude protein diet then those of other dogs. A quadratic regression equation was calculated between nitrogen intake(x) and nitrogen retention(y); y=-2.519x2+12.79x-14.79, and it was found a significantly(p<0.05) higher regression coefficient of 0.782. From the above equation, it was estimated maintenance requirement of crude protein for growing Jindo dog is 11.25g/kg BW.75/d.

• BMB Reports
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• v.32 no.6
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• pp.567-572
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• 1999

We have previously shown that a DNA fragment is responsible for the anticoagulatory effect of an earthworm, Lumbricus rubellus. The anticoagluant increased the activated partial thromboplastin time (APTT) and also inhibited the thrombin activity observed with either N-${\alpha}$-p-tosyl-L-arginine methyl ester (TAME) or H-D-phenyl-alanyl-L-pipecoil-L-arginine-p-nitroanilide (S-2238). Since trypsin digestion of the anticoagulant further increased the APTT, the possible presence of a regulatory protein for the anticoagulatory DNA was investigated by digesting the anticoagulant with trypsin and isolating the DNA fragment with C4-reversed phase HPLC. The DNA fragment lacking a regulatory protein was eluted in the flow-through fraction, and analyzed with thrombin and activated factor X. Activated factor X activity was more strongly inhibited than thrombin activity. For DNA digestion, we treated the anticoagulant with DNase and purified the DNA-binding protein with a FPLC Resource-S cation exchange column. The regulatory protein, with an $M_r$ of 55.0 kDa, reduced the anticoagulatory effect of the DNA fragment.

• Tuberculosis and Respiratory Diseases
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• v.39 no.3
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• pp.242-247
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• 1992

Background: The ability to precisely measure specific mRNA levels by hybridization to complementary DNA probes is an important tool for analyzing the regulation of gene expression. Surfactant proteins have important roles in regulating surfactant metabolism as well as in determing its physical properties. Method: The complete coding regions for rat surfactant protein complementary DNA of surfactant protein B were subcloned into pGem 3Z or 4Z such that either antisense or sense transcripts were obtained by using SP 6 RNA polymerase. Surfactant protein B mRNA was measured by filter hybridization. Results: Equation of standard curve between counts per minute (Y) and surfactant protein B mRNA transcript input (X) was Y=2034.9 X+159.1. Correlation coefficient was 1.0. Couclusions: Filter hybridization assay is suited to situation when rapid, accurate quantitation of multiple samples is required.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.726-734
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• 1989

To analyze the components of dense coat fractions associated with fat globule membrane, The membrane was treated with various concentrations of Triton X-100, a non-ionic detergent, and the composition of lipids associated to the detergent insoluble material was analyzed. The amount of protein, phospholipid, cholesterol and ganglioside in milk fat globule membrane was reduced consistently with increasing concentrations of Triton X-100. Butyrophilin (band 12), xanthine oxidase (band 3) and band 16 as constituents of insoluble coat materials was revealed after electrophorisis on SDS-polyacrylamide gels. Phosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl serine, phosphatidyl inositol and sphingomyelin were identified as the major phospholipids of the coat materials without selective concentration relative to the original membranes. Percentages of total phospholipid were not changed by any of the treatments. Fatty acids of total lipid were myristate, palmitate, stearate (major saturated acids), oleate and linoleate (major unsaturated acids). Cholesterol contents on a protein basis were slightly reduced with increasing concentrations of Triton X-100. Cholesterol adhered to protein more tightly than other constituents The contents of gangliosides was proportionally refuted with increasing concentration of Triton X-100.

• Applied Biological Chemistry
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• v.6
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• pp.79-87
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• 1965

The contents of insoluble protein nitrogen, water soluble protein nitrogen anti peptides' nitrogen were determined of the samples which were taken in seven and half hours intervals during soybean-koji preparation to study changes of soybean protein, and the contents of total nitrogen and amino nitrogen were measured for the fractions resulting from molecular sieving by using Dowex 50 having various cross linkages for the peptides from soybean-koji extracts. As the results of the studies, The followings were obtained: 1. The contents of insoluble protein nitrogen and peptides' nitrogen are fairy constant at the earlier stage, where the former decreased and the latter increased markedly as mycelia grow, then rate of the decreases and the increases of them become lower at later stage after sporulation. The contents of water soluble protein are also constant at the earlier stage until covering of mycelia over the koji and increased since then until the stage of sporulation and then decreased at the later stage. 2. The amount of peptides nitrogen in each fraction obtained by the molecular sieving was almost constant at the earlier stage and the values in fractions of X-16, X-12, X-8. X-4 and X-2 increased considerably together as mycelia grow. Then the values in the fractions showed almost plateaux, after sporulalion, where the effluent fraction showed markedly increased values throughout mycelia growth.