• BMB Reports
• /
• v.44 no.4
• /
• pp.279-284
• /
• 2011

The glutathione S-transferase (GST) system is useful for increasing protein solubility and purifying soluble GST fusion proteins. However, purifying half of the GST fusion proteins is still difficult, because they are virtually insoluble under non-denaturing conditions. To optimize a simple and rapid purification condition for GST-pyruvate kinase muscle 2 (GST-PKM2) protein, we used 1% sarkosyl for lysis and a 1 : 200 ratio of sarkosyl to Triton X-100 (S-T) for purification. We purified the GST-PKM2 protein with a high yield, approximately 5 mg/L culture, which was 33 times higher than that prepared using a conventional method. Notably, the GST-high-temperature requirement A2 (GST-HtrA2) protein, used as a model protein for functional activity, fully maintained its proteolytic activity, even when purified under our S-T condition. This method may be useful to apply to other biologically important proteins that become highly insoluble in the prokaryotic expression system.

• The Korean Journal of Food And Nutrition
• /
• v.10 no.4
• /
• pp.503-508
• /
• 1997

The extraction and separation methods of protein-bound polysaccharides from the mycelium and culture broth of L. edodes were investigated. The use 2% solution of surface active agent, Triton X-100 was effective for extraction of the protein-bound polysaccharide from the mycelium. The extraction of the protein-bound polysaccharides from mycelium with hot water was achieved by 4 hours extraction at 10$0^{\circ}C$. For the separation and partial purification of the protein bound polysaccharides the column chromatography using DEAE-Cellulose, DEAE-Sephadex and Sephadex proved to be effective.

• Korean Journal of Crystallography
• /
• v.5 no.1
• /
• pp.20-23
• /
• 1994

Specific binding to the oric region of E, coli chromsome by IciA protein inhibits initiation of chrorrnsomal replication in vitro by blocking the opening of this region effected by the initiator DnaA protein. The IciA protein has been suggested play a critical role in a key stage of the cell cycle. In order to study the structure-function relationship of IciA protein, we are determining the three-dimensional structure of IciA Votein by X-ray crystallography, As a first step toward its structure detumination E. coli IciA protein has been crystallized using sodium formate as a precipitant.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1993.11a
• /
• pp.39-40
• /
• 1993

Hepatitis B virus (HBV)is a member of the Hepadna virus family whose members share a characteristic virion structure and genome size, around 3.2kb in a paritially double-stranded form. The genome of HBV contains four overlapping open reading frames designated as P(polymerase). C(core), S(surface antigen)and X. The X gene has potential to encode 154 amino acids protein.

• Archives of Pharmacal Research
• /
• v.9 no.1
• /
• pp.29-38
• /
• 1986

The effects of ginseng saponins on the sarcolemmal $Na^{+}$, $K^{+}$-ATPase were compared to gypsophila saponin, sodium dodecylsulfate (SDS), and Triton X-100 to elucidate whether the effects are due to the membrane distruption, using a highly enriched preparation of cardiac sarcolemma prepared from dog ventricular myocardium. About 26% and 29% of vesicles in the preparation, enriched in ouabain-sensitive $Na^{+}$, $K^{+}$-ATP ase, $\beta$-adrenergic and muscarinic receptors are rightside-out and inside-out orientation, respectively. Ginseng saponins (triol>total> diol) inhibited $Na^{+}$, $K^{+}$-ATP ase activity, $Na^{+}$, $K^{+}$-ATPase activity and [$^{3}$H]ouabain binding of sarcolemmal vesicles. However, gypsophila saponin, SDS (0.4$\mu$g/$\mu$g protein) and Triton X-100 (0.6 $\mu$g/$\mu$g protein) caused about 1.35 and 1.40-fold increase in $Na^{+}$, $K^{+}$-ATPase activity and [$^{3}$H] oubain binding, respectively. Especially, the activating effect of gypsophila saponin on membrane Na+, K+ ATPase was detected at gypsophila saponin to sarcolemmal protein ratios as high as 100. Low dose of ginseng saponin (3$\mu$g/$\mu$g protein) decreased the phosphorylation sites and the concentration of ouabain binding sites (Bmax) without affecting the turnover number and affinity for ouabain binding, while gypsophila saponin, SDS(0.4 ug/ug protein), ahd Triton X-100 (0.6$\mu$g/$\mu$g protein) increased the Bmax. The results suggest that ginseng saponins cause a decrease in the number of active sites by interacting directly with $Na^{+}$, $K^{+}$-ATPase before disruption of membrane barriers of sarcolemmal vesicles.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.6
• /
• pp.973-978
• /
• 2001

The bacterial flagellar motor is a molecular machine that couples proton or sodium influx to force generation, mostly for driving rotation of the helical flagellar filament. In this study, we cloned a gene (motX) encoding a component of the sodium-driven flagellar motor from Vibrio fluvialis. The nucleotide sequence of the motX gene, composed of 633 bp and 211 amino acid residues, was determined. Overexpression of the motX gene in Escherichia coli using a strong promoter induced growth inhibition and cell lysis. The lethal effect of E. coli was suppressed by adding amiloride, as a potent inhibitor for the sodium channel. Electron microscopic observation of the expressed protein indicated that MotX protein induced by isopropyl ${\beta}$-D-thiogalactopyranoside caused the lysis of host cell.

• Molecules and Cells
• /
• v.43 no.12
• /
• pp.1023-1034
• /
• 2020

Complement fragment iC3b serves as a major opsonin for facilitating phagocytosis via its interaction with complement receptors CR3 and CR4, also known by their leukocyte integrin family names, αMβ2 and αXβ2, respectively. Although there is general agreement that iC3b binds to the αM and αX I-domains of the respective β2-integrins, much less is known regarding the regions of iC3b contributing to the αX I-domain binding. In this study, using recombinant αX I-domain, as well as recombinant fragments of iC3b as candidate binding partners, we have identified two distinct binding moieties of iC3b for the αX I-domain. They are the C3 convertase-generated N-terminal segment of the C3b α'-chain (α'NT) and the factor I cleavage-generated N-terminal segment in the CUBf region of α-chain. Additionally, we have found that the CUBf segment is a novel binding moiety of iC3b for the αM I-domain. The CUBf segment shows about a 2-fold higher binding activity than the α'NT for αX I-domain. We also have shown the involvement of crucial acidic residues on the iC3b side of the interface and basic residues on the I-domain side.

• Preventive Nutrition and Food Science
• /
• v.14 no.2
• /
• pp.123-128
• /
• 2009

This study was conducted to evaluate the weight reduction effect of yeast hydrolysate-SR101. Thirty female college students participated in a 6 week weight control program. All subjects were randomly assigned to either the placebo group, YH-SR101 (yeast hydrolysate-SR101) group, or eX diet (product of yeast hydrolysate-SR101) group. The mean energy intake of the placebo group was 1445.2${\pm}$364.0 kcal (carbohydrate: 60.1%, protein: 25.6%, fat: 14.3%), while those of the YH-SR101 and the eX diet group were 1505.6${\pm}$296.2 kcal (carbohydrate: 60.5%, protein: 22.2%, fat: 14.8%) and 1353.8${\pm}$326.3 kcal (carbohydrate: 63.2%, protein: 20.9%, fat: 15.9%), respectively. The placebo group lost 0.19${\pm}$1.14 kg of body weight, while the treatment groups (YH-SR101 and eX diet) lost 1.13${\pm}$0.83 and 1.54${\pm}$0.74 kg of body weight, respectively. There were significant differences in the decrease in body weight between the placebo and the treatment group (p<0.05). There were also significant differences in the decrease in fat mass between the placebo and treatment group (p<0.05). Furthermore, the BMI of the YH-SR101 and the eX diet groups also differed significantly before and after the diet program (p<0.05). Additionally, the BMI and waist size reduction of the treatment groups (YH-SR101 and eX diet group) differed significantly when compared to the placebo (p<0.05). The reduction of the resting metabolic rate (RMR) blood glucose, total-cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride did not differ significantly among groups. Taken together, these findings indicate that consumption of yeast hydrolysate-SR101 and eX Diet may lead to decreased body weight and fat.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.1
• /
• pp.43-47
• /
• 2008

The nickel and cobalt resistance of Cupriavidus metallidurans CH34 is mediated by the CnrCBA efflux pump encoded by the cnrYHXCBAT metal resistance determinant. The products of the three genes cnrYXH transcriptionally regulate expression of cnr. CnrY and CnrX are membrane-bound proteins, probably functioning as anti-sigma factors, whereas CnrH is a cnr-specific extracytoplasmic functions (ECF) sigma factor. The periplasmic domain of CnrX (residues 29-148) was cloned as a N-terminal His-tagged protein, expressed in Escherichia coli, and purified using affinity chromatography and gel filtration. The molecular mass was estimated to be about 13.6kDa by size exclusion chromatography, corresponding to a monomer. The tetragonal bipyramid crystals were obtained by mixing an equal volume of protein in 50mM Tris-HCl, pH 7.5, 1% glycerol, 100mM NaCl, 1mM DTT, and the reservoir solution of 15% w/v PEG 2000, 100mM lithium chloride at 277K in 2-4 days using hanging drop vapor diffusion. The protein concentration was 24mg/ml. The crystal that diffracted to $2.42{\AA}$ resolution belongs to space group $P4_1\;or\;P4_3$ with unit cell parameters of $a=b=32.14{\AA},\;c=195.31{\AA},\;{\alpha}={\beta}={\gamma}=90^{\circ}$, with one molecule of CnrX in the asymmetric unit.

• Applied Biological Chemistry
• /
• v.21 no.3
• /
• pp.193-196
• /
• 1978

Wheat quality score index was proposed as a new criterion of wheat_quality for evaluation of the laboratory testing value such as milling rate (Xm), flour ash content (Xa), flour protein content (Xp) and sedimentation value (Xs). 1) Wheat quality score index was expressed as follows; Milling score index (MSI) $=2.3X_m-72.4X_a$ Protein score index (PSI) =$5.2X_p+0.9X_{psi}$ Composite quality score index (QSI) =$0.63X_{msi}+0.37X_{psi}$ 2) The samples with the more than 100 of MSI would be the good milliability, and the samples with more than 100 of PSI would be the good bread making properties, while that with less than 100 of PSI be good pastry type properties. Whereas most of the samples with higher value of QSI would be related to the good milliability and good bread making properties. 3) MSI, PSI and QSI were significantly correlated to the each related quality components.