巻号一覧
51 巻 (2003)
- 6 号 p. 563-
- 5 号 p. 492-
- 4 号 p. 439-
- 3 号 p. 391-
- 2 号 p. 349-
- 1 号 p. 36-
51 巻, 3 号
選択された号の論文の5件中1～5を表示しています
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報文
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Takaya SATOH, Hiroyuki ITO, Toshio ICHIHARA, Hiroki SAKAE, Itsuo KATAK ...2003 年 51 巻 3 号 p. 391-397
発行日: 2003年
公開日: 2007/10/16
ジャーナル フリーThe fragmentation of doubly and triply charged mercury cluster ions were investigated. The cluster ions were produced by Xe ions bombardment on a mercury-silver amalgam. The size where evaporation and fission occur with equal probability is called appearance size. The appearance sizes of doubly and triply charged mercury cluster ions were determined to be Na2+=20, and Na3+=46, respectively. The fission channels were investigated and their probability was estimated by calculation of Q-values. The van der Waals bonding of small mercury clusters caused the symmetric fission of doubly charged cluster ions. The fission channels of triply charged cluster ions were asymmetric since the metallic character came into prominence for both precursor and large one of fission fragments.抄録全体を表示PDF形式でダウンロード (263K)
総合論文
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山垣 亮2003 年 51 巻 3 号 p. 398-406
発行日: 2003年
公開日: 2007/10/16
ジャーナル フリーIn proteomics research field, identification of proteins was performed by a combining method of mass spectrometry data and genome and DNA sequence database. This is an elegant method but it is not enough to analyze the functions of the proteins perfectly. It is essential to analyze post-translational modifications of the proteins to understand their functions in a cell. Glycosylation is one of the most important factors controlling the functions of the proteins, so a new technique of glycosylation analysis has been desired. Until now, it is difficult to perform the structure analysis of glycosylation by only mass spectrometry, because the structures of glycosylation are very complex and they have a lot of structure isomers. Post-source decay (PSD) spectra of glycosylation and oligosaccharides show the sequence of the sugar residues. PSD method is helpful to analyze their structures but the structural isomers can not be distinguished. So, we have been studying the relative abundance of the PSD ions in the MALDI-PSD spectra of oligosaccharides. Comparing the PSD spectra of the isomers, we found that their ion abundances differed. Thus, we can distinguish between the isomers of oligosacchairdes. There are general rules between the abundance of the PSD ions and the structures of the isomeric oligosaccharides.抄録全体を表示PDF形式でダウンロード (293K)
解説
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曽我 朋義2003 年 51 巻 3 号 p. 407-411
発行日: 2003年
公開日: 2007/10/16
ジャーナル フリーMetabolomics, which can be defined as the measurement of the level of all intracellular metabolites, has become a powerful new tool for gaining insight into functional biology. Intercellular metabolites not only provide metabolic phenotypes but also inducers to gene expression. Thus, metabolome analysis will be as important as genome and proteome research. However, very few methods for a large-scale metabolite analysis have been reported. This paper reports a method for the direct and quantitative analysis of charged metabolite using capillary electrophoresis electrospray ionization mass spectrometry (CE-ESI-MS). Its utility is demonstrated in the determination of basal metabolic intermediates of glycolysis and the TCA cycle pathways in Bacillus subtilis cells, yielding new information about how changes in metabolites are related to sporulation events.抄録全体を表示PDF形式でダウンロード (200K) -
山本 竜也, 月向 邦彦2003 年 51 巻 3 号 p. 412-414
発行日: 2003年
公開日: 2007/10/16
ジャーナル フリーProtein dynamics is a basis for understanding the structure-function relationships of proteins, then the magnitude and time scale of fluctuation have been widely investigated by means of various spectroscopic and relaxation methods: B-factor of X-ray crystallography, order parameter of NMR, and compressibility, etc. Among them, hydrogen/deuterium (H/D) exchange kinetics is a novel technique, which gives important information on the proton exchange rate and the number of exchangeable protons. H/D exchange of proteins has been mainly monitored by IR and NMR, but mass spectrometry has been recently utilized in this area. Mass spectrometry has various advantages: the mass change by H/D exchange can be measured with an accuracy of 1 Da using only small amount of sample even if it is a mixture involving some conformers. In this paper, we briefly introduce our method to study the H/D exchange kinetics using a MALDI-TOF-MS coupled with pepsin digestion.抄録全体を表示PDF形式でダウンロード (134K) -
佐藤 浩昭, 柴田 敦司, 吉川 博道, 田村 廣人2003 年 51 巻 3 号 p. 415-420
発行日: 2003年
公開日: 2007/10/16
ジャーナル フリーBacterial biodegradation mechanisms of non-ionic surfactants under aerobic conditions were studied by means of matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). First, biodegradation intermediates of octylphenol polyethoxylate (OPEO) were characterized by MALDI-MS. Since the formation of carboxylated OPEO (OPEC) and the changes in molecular weight distribution during biodegradation test were observed, it was proposed that the biodegradation of OPEO was proceeded mainly according to the exo-scission of EO chain accompanied with oxidation of the hydroxyl terminal side. Then, to clarify the mechanisms of the oxidative biodegradation in detail, biodegradation test was carried out using 18O-labeled water as a incubation medium. The incorporation behavior of 18O into OPEC molecules suggested that the formation of an enzyme (or coenzyme)-substrate complex linked via a covalent bond might be formed as a reaction intermediate. Finally, biodegradation profiles of non-ionic surfactants with a variety of hydrophobic moieties were investigated using 18O-labeled water. The incorporation rates of 18O into corresponding carboxylated intermediates were correlated with the hydrophobicity of the surfactants.抄録全体を表示PDF形式でダウンロード (228K)
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