<Original>Metal Species in Some Lectins Detected by Inductively Coupled Plasma Spectrometer

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。Ten commercial lectins were semi-quantitatively analyzed for their metal species by inductively coupled plasma (ICP) spectrometer. Calcium, silicon, zinc and manganese, which had been found in a lectin purified from a tree trunk, were especially analyzed. Calcium was abundant in the lectins obtained from dicotyledonous source, some of which also contained zinc and/or manganese. Calcium ions in these lectins were discussed in relation to their physiological roles. Silicon was detected in all of the lectins analyzed. Some of the lectins were phosphorylated, suggesting participation of protein kinases for their processing

Ionic liquids enable accurate chromatographic analysis of polyelectrolytes

The molecular weight distribution of polyelectrolytes was determined with high performance liquid chromatography using ionic liquids as eluents, because the electrostatic repulsion among polyelectrolytes was entirely suppressed in it. A mixed sample of polycation and polyanion was also analysed to detect them independently. © The Royal Society of Chemistry.Embargo Period 12 month

Second Order Quasi-Normal Mode of the Schwarzschild Black Hole

We formulate and calculate the second order quasi-normal modes (QNMs) of a Schwarzschild black hole (BH). Gravitational wave (GW) from a distorted BH, so called ringdown, is well understood as QNMs in general relativity. Since QNMs from binary BH mergers will be detected with high signal-to-noise ratio by GW detectors, it is also possible to detect the second perturbative order of QNMs, generated by nonlinear gravitational interaction near the BH. In the BH perturbation approach, we derive the master Zerilli equation for the metric perturbation to second order and explicitly regularize it at the horizon and spatial infinity. We numerically solve the second order Zerilli equation by implementing the modified Leaver's continued fraction method. The second order QNM frequencies are found to be twice the first order ones, and the GW amplitude is up to $\sim 10$ that of the first order for the binary BH mergers. Since the second order QNMs always exist, we can use their detections (i) to test the nonlinearity of general relativity, in particular the no-hair theorem, (ii) to remove fake events in the data analysis of QNM GWs and (iii) to measure the distance to the BH.Comment: 23 pages, no figur

Significantly high polarization degree of the very low-albedo asteroid (152679) 1998 KU2_\mathrm{2}

We present a unique and significant polarimetric result regarding the near-Earth asteroid (152679) 1998 KU$_\mathrm{2}$ , which has a very low geometric albedo. From our observations, we find that the linear polarization degrees of 1998 KU$_\mathrm{2}$ are 44.6 $\pm$ 0.5\% in the R$_\mathrm{C}$ band and 44.0 $\pm$ 0.6\% in the V band at a solar phase angle of 81.0\degr. These values are the highest of any known airless body in the solar system (i.e., high-polarization comets, asteroids, and planetary satellites) at similar phase angles. This polarimetric observation is not only the first for primitive asteroids at large phase angles, but also for low-albedo (< 0.1) airless bodies. Based on spectroscopic similarities and polarimetric measurements of materials that have been sorted by size in previous studies, we conjecture that 1998 KU$_\mathrm{2}$ has a highly microporous regolith structure comprising nano-sized carbon grains on the surface.Comment: 9 pages, 5 figures, and 3 tables, accepted for publication in A&

Renaturation of cytochrome C dissolved in polar phosphonate-type ionic liquids using highly polar zwitterions

We present a method for the renaturation of denatured cytochrome c in a phosphonate-type ionic liquid with the addition of a suitable zwitterion and a small amount of water. The polarity of zwitterions was found to be a critical property for the renaturation of cytochrome c. The renatured cytochrome c was reduced by the addition of sodium dithionite, suggesting that the renatured cytochrome c retains its redox ability. © 2017 The Chemical Society of Japan

1H NMR Analysis of cellulose in ionic liquids

[email protected] NMR spectroscopy of cellulose in a non-deuterated polar ionic liquid (IL) was carried out to analyze specific interaction between cellulose and ILs. We applied a polar IL, 1,3-dimethylimidazolium methyl methylphosphonate, as a cellulose solvent for 1H NMR spectroscopy. To prevent vanishing of the signals of hydroxyl groups (C-OHs) by hydrogen-deuterium exchange, a non-deuterated IL was utilized, and both signals for C-OHs and backbone protons were successfully detected with the aid of the no-deuterium NMR technique and a solvent suppression technique. It was confirmed that C-OHs interacted with ILs more strongly, rather than backbone protons. Furthermore, the signals of the C-OHs at 2-, 3-, and 6-position were independently observed. A strong interaction between C-OH at the 6-position and ILs was confirmed to be a key step for dissolution of cellulose. © 2014 Springer Science+Business Media Dordrecht.Embargo Period 12 month

Direct HPILC Analysis on Cellulose Depolymerisation in Ionic Liquids

Changes of average molecular weight and molecular weight distribution of cellulose in a polar ionic liquid (IL) were analysed with high performance liquid chromatography using a polar IL as an eluent (HPILC). 1-Ethyl-3-methylimidazolium methylphosphonate was used as the polar IL. As a model of partly depolymerised cellulose, a mixed sample composed of cellulose and cello-oligosaccharides (glucose, cellobiose, cellotetraose, and cellohexaose) was evaluated to test the resolution of the HPILC. In the resulting chromatograms, the corresponding peaks for each saccharide were found. Hydrolysed cellulose catalysed by a cellulase mixture in water was then prepared and dried. Then, this was dissolved in the polar IL to analyse its molecular weight distribution. The molecular weight distribution changed depending on the enzymatic reaction time. The peak for cellulose was found to decrease with the increase of the peak for cellobiose, and subsequently the peak for cellobiose decreased with the increase of that for glucose. In addition, cellulose oligomers except for cellobiose were scarcely observed, showing the catalytic feature of cellulase. Depolymerisation of cellulose in the polar IL was also carried out using ultrasonication. The peak for cellulose in the HPILC profiles shifted to a higher retention volume side and broadened with the sonication time, strongly suggesting random depolymerisation of cellulose. Thus, HPILC was confirmed to be effective for the dynamic analysis of cellulose depolymerisation. © The Royal Society of Chemistry 2013.Embargo Period 12 month