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Volume 53 (2005)
- Issue 6 Pages 305-
- Issue 5 Pages 241-
- Issue 4 Pages 183-
- Issue 3 Pages 89-
- Issue 2 Pages 53-
- Issue 1 Pages 1-
Volume 53, Issue 3
Displaying 1-11 of 11 articles from this issue
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REGULAR PAPER
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Zenzaburo TOZUKA, Wolfgang METELMANN STRUPAT, Toshifumi SHIRAGA, Rika ...2005 Volume 53 Issue 3 Pages 89-99
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESSMS2 fragments are produced by cleavage of all protonated molecules at the lone electron pairs of heteroatoms or the π electrons of double bonds of FK228. Usually, data dependent MS3 measurement cleaves only MS2 fragment of highest intensity that normally does not contain important metabolic sites. New SRM (selected reaction monitoring) data dependent exclusion MSn measurement makes it possible to obtain MS3 fragmentation data for all MS2 fragments, useful for structural determination of FK228 and its metabolites using ESI ion trap. The two different fragmentation pathways of FK228, of which fragment ions had the different elemental composition, were estimated. The accurate masses of FK228 fragment ions Fa1 (or Fb1) and Fa2 (or Fb2) were measured by LTQ FT MS to compare with those calculated exact masses. The fragmentation pathway of formers was correct as the result. LTQ FT MS accurate mass and SRM data dependent exclusion MSn measurements are required for the structure determination of FK228 and its metabolites.View full abstractDownload PDF (1023K)
COMMENTARY
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Atsushi TAKAMIZAWA, Satoko AKASHI, Kenzo HIRAOKA2005 Volume 53 Issue 3 Pages 100-107
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESSThe laser spray developed in our laboratory was applied to the analysis of biological samples. Because a 10.6 mm laser excites hydrogen bonds of water solvent, vaporization of aqueous samples takes place effectively by the laser irradiation. This makes laser spray superior to ESI for aqueous sample solution. The sensitivity of laser spray is approximately ten times higher than that of ESI for a large number of samples. The increase of signal intensities for both laser spray and ESI was observed by the addition of ammonium acetate to the sample solutions. This result was interpreted by an electrical double layer model proposed by Enke et al. The concentration of analyte ions in laser-sprayed droplets is estimated to be 10 times higher than that in the electrosprayed droplets. Noncovalent complexes were dissociated selectively to subunits by laser irradiation without dissociating the covalent bonds.View full abstractDownload PDF (807K)
INTEGRATED PAPER
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—Toward Clinical Proteomics—Kiyonaga FUJII, Toshihide NISHIMURA2005 Volume 53 Issue 3 Pages 108-116
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESSIn clinical and diagnostic proteomics that requires an analysis of a large number of human samples, it is essential to develop a comprehensive and robust system for proteome analysis. Our strategy for quantitative protein profiling has been performed by two approaches; both “gel-based” and “shotgun” proteomics. Gel-based proteomics consists of two-dimensional polyacrylamide-gel electrophoresis (2-D PAGE) for quantitative analysis of the separated intact proteins and mass spectrometry for protein identification. Simultaneously, shotgun proteomics has been conducted by the quantitative protein profiling approach for peptide fragments after digestion of whole protein mixture, based on multi-dimensional liquid chromatography and tandem mass spectrometry (LC/MS/MS). Therefore, we have constructed high-throughput and -sensitive 1-D LC/MS/MS systems with a micro-flow LC system and a linear ion-trap mass spectrometer for an approach using 2-D PAGE. Additionally, high-resolution and fully automated online 2-D LC/MS/MS systems have been constructed for comprehensive protein profiling. Currently, we have applied Fourier-transform mass spectrometry (FT-MS) to our protein profiling system. These LC/MS/MS systems described here are capable of high resolution peptide mapping, which is sufficient to comprehensively identify highly complex biological mixture with a reasonably high throughput. These integrated systems could be used as a promising technical platform toward bedside practice of clinical proteomics.View full abstractDownload PDF (1547K)
COMMENTARY
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Masaki MATSUMOTO, Keiichi NAKAYAMA2005 Volume 53 Issue 3 Pages 117-124
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESSProtein phosphorylation is a reversible post-translational modification crucial in signal transduction. To understand signaling processes, it is important to identify phosphorylated proteins and their phosphorylation sites. Because phosphorylation is a dynamic process, elucidation of signaling networks also requires quantitation of these phosphorylation events. This report summarizes recent advances in techniques for phospho-proteomics by using mass spectrometry. In this review, we offer an overview of the several technologies to elucidate phosphoproteome currently available. These technologies involve the enrichment of phosphorylated proteins/peptides and identification and quantification by mass spectrometry.View full abstractDownload PDF (895K) -
Yasuhide NAITO2005 Volume 53 Issue 3 Pages 125-132
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESSMass microprobe acquires mass-to-charge ratios of ions which are generated at an extremely small area on the sample surface. A raster achieved by moving the area of ionization over the sample surface allows to map a wide variety of compounds existing on the surface with a lateral resolution of 1-100 μm. The technology to visualize a local distribution of compounds in the sample is called imaging mass spectrometry and is recognized as an emerging field of mass spectrometry in recent years. Mass microprobe can now be applied to biological samples, such as thin tissue sections, after significant progress of sample preparation techniques. SIMS, LDI, and MALDI are ionization methods utilized in mass microprobe. Molecular images of light compounds, such as lipids or metabolites, are suited to be recorded by SIMS or LDI, whereas peptides and proteins are targeted by MALDI. Although the sensitivity is the most important issue still to be overcome, mass microprobe is superior to optical observations for providing chemical information on biological samples, and is highly promising as a practical tool of biological researches in very near future.View full abstractDownload PDF (1198K) -
Yosuke SHIGEMATSU, Ikue HATA, Yukie TANAKA2005 Volume 53 Issue 3 Pages 133-136
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESSElectrospray ionization tandem mass spectrometry enables us the sensitive and quantitative analysis of many ionic compounds with high polarity, such as acylcarnitines and amino acids. In newborn screening programs using this new technology, many inborn errors of metabolism can be diagnosed simultaneously by the measurement of one small punch of blood spots. Quality of life of patients with target diseases is thought to be improved by early medical intervention to prevent sudden death in infancy or brain damage. Based on the limitation of this program recognized, methodological difficulties to be overcome in view of the false negative and false positive rate and modifications in our program are described.View full abstractDownload PDF (504K) -
Yasuhiro SUZUKI, So NAKAGAWA, Takeshi HASE, Sohichi OGISHIMA, Hiroshi ...2005 Volume 53 Issue 3 Pages 137-141
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESSThe specificity in topology of the protein network of yeast was investigated by analysis of the number of the protein-protein interactions. In order to examine the specificity of the protein network, the proteins was classified into three layers; the low, middle, and high with respect to the number of the protein-protein interactions. In the middle layer, proteins were mainly interconnected to each other, so proteins in the high layer were forced to be wired to those in the low layer. Hence, the results indicates that the proteins in the high layer connected between the low layer and the middle layer and integrated the network as a whole. Chracterization of each layer was carried out biologically. It seems that in the past, studies have been focussed on the proteins in the high layer (highly connected proteins), but in the future, studies on the proteins in the middle layer will be more siginificant topologically and biologically.View full abstractDownload PDF (669K) -
—View from Pharmacokinetics and Drug Metabolism—Toshihiko IKEDA2005 Volume 53 Issue 3 Pages 142-145
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESSIdiosyncratic drug toxicity is a rare, toxic drug reaction found only in the drug-treated patients clinically, and is not reproducible in animal experiments. In many cases, this toxicity is initiated quite likely by a production of chemically reactive metabolites, which covalently bind to macromolecules such as proteins and nucleic acids unless otherwise detoxified by glutathione S-transferases or other scavenging enzymes. Drug-modified proteins, particularly those present in the supernatant fraction, are generally processed to peptide fragments by a proteasome. These peptides are transported to the cell surface after binding to the major histocompatibility complex class I (MHC-I), and presented to the immune system. It is believed that abnormal peptides, when recognized by cytotoxic T-lymphocytes as non-self peptides, induce the toxic immune reaction finally leading to the cell death. Idiosyncrasy would reside on 1) production of the chemically reactive metabolites, 2) degradation of the reactive metabolites, and 3) recognition of drug-modified proteins as non-self proteins by the immune system. In order to prevent the idiosyncratic drug toxicity, organic chemists need to establish a strategy donating the structural nature being hardly converted to the reactive forms to the drug molecules. To detect the chemically reactive metabolites, highly sensitive detection of glutathione conjugate, produced by incubating the parent drug with liver microsomes in the presence of NADPH and glutathione, by a neutral loss scan set at 129 using LC/MS/MS could be utilized. A high pharmacological potency of the drug that eventually leads to a reduced dose level not higher than 10 mg/body would be another avenue to circumvent the idiosyncratic drug toxicity.View full abstractDownload PDF (448K)
REVIEW
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Akira TSUJI2005 Volume 53 Issue 3 Pages 146-156
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESSIn the past decade, a comprehensive list of membrane transporters has become available owing to the progress in genome analysis, as well as extensive membrane physiological and molecular biological studies on membrane transporters. Major membrane transporters have been classified into the solute carrier (SLC) transporter family and the ATP-binding cassette (ABC) transporter family. The SLC family consists of 43 gene subfamilies and a total of about 319 family members, including ion-coupled transporters, facilitated transporters, and exchangers. In the ABC transporter family, 49 genes have been identified and classified into nine subfamilies. Some of these transporters accept not only physiological or endogenous substrates, but also xenobiotics, including drugs. Such drug transporters are very important, because they play pivotal roles in determining the pharmacokinetic profiles of particular drugs and thereby determine the overall pharmacological effects, i.e., drug absorption, distribution, elimination, and concentration at the target sites. This review aims to provide clues that will allow us to establish efficient strategies to use transporters for target and lead discovery.View full abstractDownload PDF (1404K) -
Noriko TSUNODA2005 Volume 53 Issue 3 Pages 157-163
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESS2004 was the 10th anniversary of the Matsumoto sarin incident, and 2005 is the 10th anniversary of the Tokyo Subway Attack. National Research Institute of Police Science has been engaged in forensic examinations into these incidents. Chemical analyses of the victim's blood, water, soil, and wipe samples were performed by organic solvent extraction, followed by gas chromatography-mass spectrometry with or without tert-butyldimethylsilylation. As a result, sarin and its hydrolysis products (isopropylmethyl phosphonate and methylphosphonate), derived from sarin were positively identified by their mass spectra and retention indices. Furthermore, from the chemical analysis of evidence samples taken from the scene of manufacturing plant, precusors, and byproducts corresponding to synthetic routs of sarin has been identified. This paper presents characteristics of nerve agents, sample preparation of sarin, optimization of GC-MS, and case reports from a standpoint of effectiveness of GC-MS.View full abstractDownload PDF (790K)
NOTE
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Ryo YAMASHITA, Kazuki YASUDA, Yasushi KABURAGI2005 Volume 53 Issue 3 Pages 164-168
Published: 2005
Released on J-STAGE: April 05, 2006
JOURNAL FREE ACCESSTwo-dimensional liquid chromatography coupled with tandem mass spectrometry (2D LC-MS/MS) technique has high capability of resolving peptides, and is used for analysis of highly complex protein mixtures. In this report, we used this technique to analyze proteins secreted from human hepatoma cell line, HepG2, and identified over 400 secreted proteins. Recently, liver has been demonstrated to secrete proteins in the same manner as adipocytes which secrete adipocytokines regulating lipid and glucose metabolism. As the hepatic lipid homeostasis is regulated by a cross talk between peroxisome proliferator-activated receptor-alpha and liver X receptor (LXR), both of which are nuclear receptors, we attempted to identify the LXR-regulated proteins secreted from HepG2 cells using the two-dimensional differential in-gel electrophoresis technology (2D-DIGE) followed by the identification of proteins with significantly different expression using LC-MS/MS. We identified one of the upregulated proteins in response to LXR activation as apolipoprotein E. These findings indicate that the combinatorial mass spectrometry-based approach utilizing multi-dimensional chromatography and two-dimensional electrophoresis is useful to identify the target molecules for clinical drugs from complex protein mixtures.View full abstractDownload PDF (834K)
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