巻号一覧
56 巻, 1 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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一般論文
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寺本 華奈江, 孫 麗偉, 佐藤 浩昭, 鳥村 政基, 田尾 博明, 新谷 智吉2008 年 56 巻 1 号 p. 1-11
発行日: 2008/02/01
公開日: 2008/02/26
ジャーナル フリーRibosomal subunit proteins of eight genome-sequenced lactic acid bacteria (LAB) were characterized by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) to provide a guideline for selecting reliable biomarkers used for the rapid identification of LAB. Subunit proteins with molecular weight over ca. 20,000 were typically difficult to detect. This phenomenon appeared to be due to the mass discrimination effect in MALDI-MS. Conserved post-translational modifications excluding N-terminal methionine loss were investigated by comparing the mass differences from sequence masses calculated from the amino acid sequences of the proteins with the post-translational modifications. Various errors in the amino acid sequences of the subunit proteins registered in protein databases could be detected by comparing amino acid sequences, and corrected by inspecting gene sequences. By eliminating the subunit proteins with higher molecular weight and post-translational modifications as well as other difficult to detect subunit proteins, 27 subunit proteins were finally selected as the reliable biomarkers.抄録全体を表示PDF形式でダウンロード (1112K) -
生方 正章, 草井 明彦, 大須賀 潤一, 田中 一夫, 金子 竹男, 小林 憲正2008 年 56 巻 1 号 p. 13-19
発行日: 2008/02/01
公開日: 2008/02/26
ジャーナル フリーType analysis of crude oil and petroleum products has been studied using a gas chromatograph/time-of-flight mass spectrometer. The use of inert fused silica capillary tube inlet/field ionization (blank tube inlet/FI) is a suitable method for analyzing low boiling point components. Field ionization (FI) and field desorption (FD) methods are classified as soft ionization. Therefore, those ionization methods are used to analyze samples in which the molecular ion is hardly detected on electron ionization, as in the case of hydrocarbons. Type analysis using blank tube inlet/FI, capillary gas chromatography/FI (GC/FI), and FD mass spectra provides useful information, such as the average molecular weight. We examined the composition of crude oil and some petroleum products by type analysis using blank tube inlet/FI, capillary GC/FI, and FD. We carried out type analysis using six series of components. These were CnH2n+2, CnH2n, CnH2n-2, CnHn-4, CnHn-6, and CnHn-8. The averaged molecular weight by FD was much higher than that by blank tube inlet/FI, because it is difficult to measure low boiling point components by FD. In the blank tube inlet/FI method, all components were introduced and ionized. Therefore, this method is much more suitable than other methods for evaluating the composition of crude oil and petroleum products.抄録全体を表示PDF形式でダウンロード (692K)
解説
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吉野 健一2008 年 56 巻 1 号 p. 21-22
発行日: 2008/02/01
公開日: 2008/02/26
ジャーナル フリーPDF形式でダウンロード (148K)
Letter to the Editor
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佐々木 智啓2008 年 56 巻 1 号 p. 23-26
発行日: 2008/02/01
公開日: 2008/02/26
ジャーナル フリーPDF形式でダウンロード (1381K)
Letter from the Editor-in-Chief
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吉野 健一2008 年 56 巻 1 号 p. 27-32
発行日: 2008/02/01
公開日: 2008/02/26
ジャーナル フリーThe terms “accurate mass” and “exact mass” are not synonymous in mass spectrometry. Accurate mass refers to the mass value of an ion or radical determined experimentally by mass spectrometry. On the other hand, exact mass refers to the mass value of a single ion, radical, or molecule calculated by summing the mass values of individual isotopes. To avoid confusion, “measured accurate mass” and “calculated exact mass” should be used in place of “accurate mass” and “exact mass,” respectively.抄録全体を表示PDF形式でダウンロード (847K)
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