• Genomics & Informatics
• /
• v.14 no.3
• /
• pp.112-124
• /
• 2016

Solid tumor is generally observed in tissues of epithelial or endothelial cells of lung, breast, prostate, pancreases, colorectal, stomach, and bladder, where several genes transcription is regulated by the microRNAs (miRNAs). Argonaute (AGO) protein is a family of protein which assists in miRNAs to bind with mRNAs of the target genes. Hence, study of the binding mechanism between AGO protein and miRNAs, and also with miRNAs-mRNAs duplex is crucial for understanding the RNA silencing mechanism. In the current work, 64 genes and 23 miRNAs have been selected from literatures, whose deregulation is well established in seven types of solid cancer like lung, breast, prostate, pancreases, colorectal, stomach, and bladder cancer. In silico study reveals, miRNAs namely, miR-106a, miR-21, and miR-29b-2 have a strong binding affinity towards PTEN, TGFBR2, and VEGFA genes, respectively, suggested as important factors in RNA silencing mechanism. Furthermore, interaction between AGO protein (PDB ID-3F73, chain A) with selected miRNAs and with miRNAs-mRNAs duplex were studied computationally to understand their binding at molecular level. The residual interaction and hydrogen bonding are inspected in Discovery Studio 3.5 suites. The current investigation throws light on understanding miRNAs based gene silencing mechanism in solid cancer.

• Journal of the Korean Magnetic Resonance Society
• /
• v.16 no.2
• /
• pp.103-110
• /
• 2012

Membrane proteins play a essential role in the biological systems and it is not easy to handle a membrane protein for its structural study. Solid-state NMR (ssNMR) can be a good tool to investigate the structures and dynamics of membrane proteins. In ssNMR, Magic Angle Spinning (MAS) and Cross Polarization (CP) can be utilized to reduce the line-broadening, leading to high resolution and sensitivity in the spectrum. ssNMR, if combined with other spectroscopic methods, can provide us a enough knowledge on structures and dynamics of membrane proteins in biological condition.

• KSBB Journal
• /
• v.16 no.5
• /
• pp.500-504
• /
• 2001

We scaled up a covalent immobilization system of urokinase to the activated Sepharose and used it repeatedly to cleava a fusion protein consisting of human growth hormone and GST fragment. After scale up from 6 ml to 250 ml. the column system still demonstrated basically the same performance in terms of urokinase immobilization and fusion protein cleavage. When the column was washed with 6 M guanidine HCI after the cleavage reaction, the immobilized urokinase showed no activity probably becasue it was fully unfoled. However, as the denaturant was gradually removed from the column the immobilized urokinase fully regained its bioactivity, which indicated it was properly refolded into is natie conformation as covalently attached to the solid matrix. After 20 cycles of this solid-phase unfolding/refolding. the immobilized urokinase maintained approx. 80% of the initial bioactivity. This method provides and efficient protocol to apply the solid-phase refolding technique to improve the longevity of immobilized enzyme columns.

• Preventive Nutrition and Food Science
• /
• v.8 no.3
• /
• pp.278-283
• /
• 2003

Textural properties of tofu manufactured with micronized full-fat soyflour (MFS) were enhanced by the addition of soy protein isolate, whey protein concentrate, chitosan oligosaccharide and mushroom powder. The MFS solution (14.2% solid content) was converted to semi-solid tofu by a two-stage heat treatment with the addition of 4% coagulant mix. The MFS tofu was evaluated by a compression test as well as sensory evaluation. To produce the semi-solid gel (MFS tofu) with reasonably high strength and toughness, the MFS solution with 14.2% solid content and 7.0% protein had to be heat treated at 121$^{\circ}C$ for 3min. The relative toughness of MFS tofu was increased by the addition of SPI, showing a 144% increase. The toughness of MFS tofu prepared with the MFS/SPI mixture was greatly increased by the addition of WPC at the level of 0.7% and the water separation from MFS tofu was greatly reduced. Furthermore, the toughness and strength of MFS/SPI tofu was enhanced by the addition of 0.1% chitosan oligosaccharide and 0.2% mushroom powder. The sensory evaluation of the tofu fortified with SPI, chitosan oligosaccharide and mushroom powder was superior to that of MFS tofu, with a higher score for overall preference.

• Mycobiology
• /
• v.34 no.3
• /
• pp.128-130
• /
• 2006

The solid waste of sago industry using cassava was fermented by Aspergillus niger, Aspergillus terreus and Rhizopus stolonifer in solid state fermentation. Cassava waste contained 52 per cent starch and 2.9 per cent protein by dry weight. The amylase activity was maintained at a high level and the highest amylase activity was observed on the $8^{th}$ day in R. stolonifer mediated fermentation. R. stolonifer was more efficient than Aspergillus niger and Aspergillus terreus in bioconverting cassava waste into fungal protein (90.24 mg/g) by saccharifying 70% starch and releasing 44.5% reducing sugars in eight days of solid state fermentation.

• Bulletin of the Korean Chemical Society
• /
• v.24 no.9
• /
• pp.1281-1283
• /
• 2003

Proteins in highly oriented lipid bilayer samples are useful to study membrane protein structure determination. Planar lipid bilayers aligned and supported on glass slide were prepared. These stack of glass slide with planar lipid bilayers are not well fit for commercial solid-state NMR probe with round coil. Therefore, homebuilt solid-state NMR probe was built and used for a stack of thin glass plates and RF coil is wrapping directly around the flat square sample. The overall filling factor of the coil is much better and the large surface area enhances the extent to orientation by providing uniform environments for the phospholipids and the high ratio of circumference to area reduces edge effects. $^1H\;and\;^{15}N$ double resonance probe for 400 MHz NMR (9.4T) with a flat coil (coil size: 11 mm ${\times}$ 20 mm ${\times}$ 4 mm) is constructed and tested.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.9
• /
• pp.2007-2010
• /
• 2009

Donepezil hydrochloride is a reversible acetylcholinesterase inhibitor that is used in the treatment of Alzheimer’s disease to improve the cognitive performance. It shows different crystalline forms including hydrates. Therefore, it is very important to confirm the polymorphic forms in the formulations of pharmaceutical materials because polymorphs of the same drug often exhibit significant differences in solubility, bioavailability, processability and physical/chemical stability. In this paper, four different forms of donepezil hydrochloride were prepared and characterized using X-ray powder diffraction, Fourier transform infrared, and solid-state nuclear magnetic resonance (NMR) spectroscopy. This study showed that solid-state NMR spectroscopy is a powerful technique for obtaining structural information and the polymorphology of pharmaceutical solids.

• KSBB Journal
• /
• v.16 no.2
• /
• pp.146-152
• /
• 2001

To avoid the intrinsic problem of aggregation associated with the traditional solution-phase refolding process, we propose a solid-phase refolding method integrated with expanded bed adsorption chromatography. The model protein used was a fusion protein of recombinant human growth hormone and a glutathione S transferase fragment. It was demonstrated that the EBA-mediated refolding technique could simultaneously remove cellular debris and directly renature the fusion protein inclusion bodies in the cell homogenate with much higher yields and less agregation. To demonstrate the applicability of the method, we successfully tested the three representative types of starting materials, i. e., rhGH monomer, washed inclusion bodies, and the E. coli homogenate. This direct and simplified refolding process could also reduce the number of renaturation steps required and allow refolding at a higher concentration, at approximately 2 mg fusion protein per ml of resin. To the best of our knowledge, it is the first approach that has combined the solid-phase refolding method with expanded bed chromatography.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.5
• /
• pp.509-514
• /
• 2003

We performed the experiment to determine the effective factors, such as the initial concentration of protein, pore size of air distributor, SAV (superficial air velocity), pH, salts and temperature related to foaming characteristics. The foam height in a foam generator was increased with the increase of the initial protein concentration and the decrease of pore size. As SAV was increased, the foam height was increased, and the optimum SAV was 0.84 cm/sec. The foam height was highest in the acid region and it was increased with the increase of salt concentration of NaCl and $NaHCO_3.$ The removal efficiencies of TSS (total suspended solid) and turbidity decreased with the increase of the initial protein concentration in the batch foam separator.

• Korean Chemical Engineering Research
• /
• v.43 no.2
• /
• pp.187-201
• /
• 2005

Bioprocessing technologies utilizing 'biorecognition' between a solid matrix and a protein is being widely experimented as a means to replacing the conventional, solution-based technology. Frequently the matrices are chromatographic resins with specific functional groups exposed outside. Since the reactions of and interactions with the proteins occur as they are attached to the solid matrix, this 'solid-phase' processing has distinct advantages over the solution-phase technology. Solid-phase refolding of inclusion body proteins uses ion exchange resins to adsorb denaturant-dissolved inclusion body. As the denaturant is slowly removed from the micromoiety around the protein, it is refolded into a native, three-dimensional structure. Once the refolding is complete, the folded protein can be eluted by a conventional elution technique such as the salt-gradient. This concept was successfully extended to 'EBA (expanded bed adsorption)-mediated refolding,' in which the denaturant-dissolved inclusion body in whole cell homogenate is adsorbed to a Streamline resin while cell debris and other impurity proteins are removed by the EBA action. The adsorbed protein follows the same refolding steps. This solid-phase refolding process shows the potential to improve the refolding yield, reduce the number of processing steps and the processing volume and time, and thus improve the overall process economics significantly. In this paper, the experimental results of the solid-phase refolding technology applied to several biopharmaceutical proteins of various types are presented.