• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.258-261
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• 2006

The addition of zeolite particles enhances the stability of mRNA molecules in a cell-free protein synthesis system. When $20{\mu}g/{\mu}L$ of zeolite (Y5.4) is added to a reaction mixture of cell-free protein synthesis, a substantial increase in protein synthesis is observed. The stabilizing effect of zeolite is most dearly observed in an in vitro translation reaction directed by purified mRNA, as opposed to a coupled transcription and translation reaction. Upon the addition of zeolite in the in vitro translation reaction, the life span of the mRNA molecules is substantially extended, leading to an 80% increase in protein synthesis. The effect of zeolite upon the mRNA stability appears be strongly related to the cation exchange (potassium to sodium) reaction. Our results demonstrate the possibility of modifying this biological process using heterogeneous, non-biological substances in a cell-free protein synthesis system.

• Molecules and Cells
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• v.44 no.8
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• pp.623-625
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• 2021

• Molecules and Cells
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• v.46 no.10
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• pp.589-591
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• 2023

• Molecules and Cells
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• v.26 no.6
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• pp.530-535
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• 2008

Optical signals based on Raman scattering, coherent anti-Stokes Raman scattering (CARS), and harmonic generation can be used to image biological molecules in living cells without labeling. Both Raman scattering and CARS signals can be used to detect frequencies of molecular vibrations and to obtain the molecular distributions in samples. Second-harmonic optical signals can also be generated in structured arrays of noncentrosymmetric molecules and can be used to detect structured aggregates of proteins, such as, collagen, myosin and tubulin. Since labeling techniques using chemical and biological reactions may cause undesirable changes in the sample, label-free molecular imaging techniques are essential for observation of living samples.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.111-111
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• 2001

The relationship between selenium and signal molecules is not well elucidated yet. It was found that physiological concentration of selenite, less than 3 $\mu$M, reduced ASKl activity and induced of PI3-Kinase/Akt pathways in HT1080 cells. Duration of these signal molecules by selenite was much longer than that by growth factors and other stresses. The longer duration time of these signal molecules may be important to maintain normal functions against stresses.(omitted)

• Journal of the Optical Society of Korea
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• v.12 no.3
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• pp.170-173
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• 2008

In this study, we simulated a statistical model of FCS(fluorescence correlation spectroscopy) based on a Poisson process to understand and explain observations of the experiment performed on molecules of ultra-low concentration by the home-built laser-scanning confocal microscope. The statistical model confirmed that the relative mean square amplitude of fluctuations is shown to be inversely proportional to the average number of molecules, even in the ultra-low concentration, if some conditions are satisfied. Signal-to-noise ratio and the variability of dwelling time under the confocal volume were found to be effective conditions for the experiment.

• Journal of Environmental Science International
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• v.25 no.7
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• pp.927-935
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• 2016

Dissolved oxygen is necessary for many biological processes as well as many industrial practices. Dissolved oxygen released from water in dissolved air flotation (DAF) systems can be have many different applications. However, DAF systems are very costly to operate. To develop more efficient DAF systems, a deeper understanding of the process of oxygen being released from water is required. In this study, molecular dynamics (MD) simulations were used to simulate 100 oxygen molecules surrounded by 31002 water molecules at temperatures ranging from $0^{\circ}C$ to $100^{\circ}C$. Simulations were carried out for 10 ns, during which, in most cases, all the oxygen molecules were released from the water droplet. With MD simulations, visualization of the molecules escaping the water droplet was possible, which aided the understanding of the interactions between molecules at the nano-scale. The results showed that as the oxygen molecules moved near the edge of the water droplet that the oxygen molecules hesitated before escaping the water droplet or returned to the interior of the water droplet. This was because of the attractive forces between the water and oxygen molecules. Moreover, after most of the oxygen molecules were released from the droplet, some were found to return to the droplet's edge or even the interior of the droplet. It was also confirmed that oxygen molecules were released at a faster rate at higher temperatures.

• Molecules and Cells
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• v.23 no.2
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• pp.252-257
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• 2007

Escherichia coli HslVU is an ATP-dependent protease consisting of two heat shock proteins, the HslU ATPase and HslV peptidase. In the reconstituted enzyme, HslU stimulates the proteolytic activity of HslV by one to two orders of magnitude, while HslV increases the rate of ATP hydrolysis by HslU several-fold. Here we show that HslV alone can efficiently degrade certain unfolded proteins, such as unfolded lactalbumin and lysozyme prepared by complete reduction of disulfide bonds, but not their native forms. Furthermore, HslV alone cleaved a lactalbumin fragment sandwiched by two thioredoxin molecules, indicating that it can hydrolyze the internal peptide bonds of lactalbumin. Surprisingly, ATP inhibited the degradation of unfolded proteins by HslV. This inhibitory effect of ATP was markedly diminished by substitution of the Arg86 residue located in the apical pore of HslV with Gly, suggesting that interaction of ATP with the Arg residue blocks access of unfolded proteins to the proteolytic chamber of HslV. These results suggest that uncomplexed HslV is inactive under normal conditions, but may can degrade unfolded proteins when the ATP level is low, as it is during carbon starvation.

• Advances in nano research
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• v.1 no.3
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• pp.133-151
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• 2013

The availability of advanced nanotechnological methodologies (experimental and theoretical) has widened the investigation of biological/organic matter in interaction with substrates. Minerals are good candidates as substrates because they may present a wide variety of physico-chemical properties and surface nanostructures that can be used to actively condense and manipulate the biomolecules. Scanning Probe Microscopy (SPM) is one of the best suited techniques used to investigate at a single molecule level the surface interactions. In addition, the recent availability of high performance computing has increased the possibility to study quantum mechanically the interaction phenomena extending the number of atoms involved in the simulation. In the present paper, firstly we will briefly introduce new SPM technological developments and applications to investigate mineral surfaces and mineral-biomolecule interaction, then we will present results on the specific RNA-mineral interaction and recent basics and applicative achievements in the field of the interactions between other fundamental biological molecules and mineral surfaces from both an experimental and theoretical point of view.

• Molecules and Cells
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• v.41 no.1
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• pp.50-54
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• 2018

Atg5 and Atg7 have long been considered as essential molecules for autophagy. However, we found that cells lacking these molecules still form autophagic vacuoles and perform autophagic protein degradation when subjected to certain stressors. During this unconventional autophagy pathway, autophagosomes appeared to be generated in a Rab9-dependent manner by the fusion of vesicles derived from the trans-Golgi and late endosomes. Therefore, mammalian autophagy can occur via at least two different pathways; the Atg5/Atg7-dependent conventional pathway and an Atg5/Atg7-independent alternative pathway.