JMSSJ On-line Abstracts, Vol.48, No.5 (2000)
Kazuo HIRAYAMA (Central Research Laboratories Ajinomoto Co., Inc. ,1-1Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan)
J. Mass Spectrom. Soc. Jpn., 48(5), 289-297, 2000
The development of biochemistry and molecular biology has enabled to study the mechanism of various biological systems, such as protein-protein interactions. However, structural biology has been successfully applied to only a few studies of protein-protein interactions. As the development of technologies of X-ray crystallography and nuclear magnetic resonance spectrometry (NMR), it is now possible to obtain precise information on the tertiary structure of proteins. Mass spectrometry is also an effective tool to analyze the structure of large biomolecules. In addition, computational chemistry plays an important role in the study of the protein-ligand interaction. This paper demonstrates how effective mass spectrometry is in the studies of structure-function relationships of biomolecule networks. Prospects of the mass spectrometers for the study of protein structure is also discussed.
Chiaki UYEDA
J. Mass Spectrom. Soc. Jpn., 48(5), 298-302, 2000
The isotope mass fractionations of various refractory inclusions observed in the primitive materials as well as its estimated thermal origin are reviewed, which are generally inconsistent with the origins estimated by other procedures. The temperature dependence was studied for the mass fractionation of condensates produced form Mg-silicate gas in the evaporation-condensation experiment. The 26Mg/24Mg values of the condensates with respect to the starting material fractionated both in the heavy and light isotopes. The theoretical relationship of the condensates showed good agreement with the experimental values. It has revealed that the amount of mass fractionation cannot be a simple indicator to judge whether the inclusion was a condensate or an evaporation resid
ue. Rayleigh mass fractionation occurs under a restricted condition. It is necessary to know the actual fractionation coefficient in the nebula, in order to discuss the relationship between the mass loss of a depleted element and its isotope fractionation in the primitive planetary bodies in terms of the Rayleigh distillation process.
Hisashi MATSUDA (Emeritus Professor of Osaka University, 2-27-19 Kiyoshikojin, Takarazuka 665-0836, Japan)
J. Mass Spectrom. Soc. Jpn., 48(5), 303-305, 2000
A new design of TOF mass spectrometer with spiral orbit is proposed. By the suitable arrangement of electric sector fields and free spaces, ion optical systems with spiral orbit are found. The long orbit has no overlapping part in comparison with the multi-turn system. The ion path length of more than 3 m is possible to obtain in a very small geometrical space of only 20 cm diameter. The systems have excellent focusing nature in both time and space.
Y. FUJITA,*a) H. FUJITA,a) G. P. A. BERG,b) K. HARADA,a) K. HATANAKA,c) M. KAWABATA,d) T. NORO,c) H. SAKAGUCHI,d) T. SHINADA,a) Y. SHIMBARA,a) T. TAKI,d) H. UENO,a) and M. YOSOId) (*a)Department of Physics, Osaka University (Toyonaka, Osaka 560-0043, Japan), b)Indiana University Cyclotron Facility (Bloomington, Indiana 47408, USA), c)Research Center for Nuclear Physics, Osaka University (Ibaraki 567-0047, Japan), d)Department of Physics, Kyoto University (Sakyo, Kyoto 606-8224, Japan))
J. Mass Spectrom. Soc. Jpn., 48(5), 306-311, 2000
Introduction of a magnetic spectrome
ter for the analysis of nuclear reaction products can open a new dimension in structure studies as well as reaction studies through the capability of achieving high-resolution and low-background measurements. Ion-optical matching methods to achieve better energy (momentum) resolutions than those inherent to the incident beam causing the reaction are described for a magnetic spectrometer using beams from an accelerator. They are the lateral dispersion matching, focus matching and also the kinematic correction. In addition the angular dispersion matching should be performed if better resolution of the scattering angle is important. These conditions are described in the first order approximation of ion optics. The diagnostic methods to realize the conditions of lateral dispersion matching and angular dispersion matching condition are briefly presented. The method described here can be applied for a good resolution spectroscopy of a reaction using a beam from ion source or a secondary beam with a larger energy spread.
Michisato TOYODA, Daisuke OKUMURA, Shin-ichi YAMAGUCHI, Morio ISHIHARA, Itsuo KATAKUSE, and Takekiyo MATSUO (Department of Physics, Graduate School of Science, Osaka University, 1-16 Machikaneyama, Toyonaka, Osaka 560-0043, Japan)
J. Mass Spectrom. Soc. Jpn., 48(5), 312-317, 2000
A new type of multi-turn time-of-flight (TOF) mass spectrometer was constructed, consisting of four cylindrical electric sectors and 28 electric quadrupole lenses, the size of the vacuum chamber being 60 cm×70 cm×20 cm. As the mass resolution of a TOF mass spectrometer is proportional to the path length, it will be necessary to use multi-turn optics in order to achieve the desired resolution within the physical limitations imposed by the spacecraft. It was demonstrated that the mass resolution can be in
creased according to the number of cycles of the ions through the ion optical system. The mass resolution was 68,000 (m/z= 28, FWHM) after 150.5 cycles.
Hiroshi NISHIMURA,a) Keiji HISAYOSHI,a) Hideyuki NAKAMURA,a) Yuriko NISHI,a) Shinya OTA,a) Tomoe HATAKEYAMA,a) Takeshi KOZAI,a) Hiroaki OZAWA,a) and Mamoru MURATAa) (a)Department of Geological Sciences, Faculty of Science, Naruto University of Education, (748, Nakashima, Taka-shima, Naruto, Tokushima 772-8502, Japan)
J. Mass Spectrom. Soc. Jpn., 48(5), 318-322, 2000
A trial modification was carried out to the conventional surface (thermal) ionization ion source. A direct sample loading of milligram sized chip of solid sample completely free from terrestrial chemical additional reagents is adopted in the modification. A milligram sized block sample is set into a kind of boat filament made of tantalum, heated and evaporated in the form of atomic vapor with no addition of silica gel or phosphoric acid. This point is perfectly different from other previous works of direct loading methods. The atoms are ionized at the surface of the side filament made of rhenium. The direct loading ionization system was installed in a virtual image compact double focusing mass spectrometer whose mass resolving power is reached over 5,000. As an example of isotope analysis, a 0.5 mg weighed chip of commercially sold pure magnesium metal was loaded as a sample. It gave reasonable isotope ratio 25Mg/24Mg=0.12472±0.00045 and 26Mg/24Mg=0.13564±0.00050; d26=0.15%o. Several terrestrial mineral samples, forsterite, enstatite, hypersthene, hornblende, and serpentine were also analyz
ed for magnesium isotope ratios, and 26's for those samples were distributed -1.7%o to +4.9%o. Although the reproducibility of isotope analysis is ±3.5%o, and may be comparatively too large to apply the detection of minute isotope anomaly, the newly developed ion source was found to be usable for the isotope analysis of a milligram sized solid samples by the method of direct loading completely free from the additives of chemical reagents.
Masami SAWADA*a), Kouji HAGITAb), Hiroyuki IMAMURAa), Hiroyuki TABUCHIb), Shinya YODOYAb), Maki UMEDAc), Yoshio TAKAIa), Hitoshi YAMADAa), Hiroshi YAMAOKAc), Keiji HIROSEd), Yoshito TOBEd), Toshikazu TANAKAb), and Shigetoshi TAKAHASHIa) (*a)Materials Analysis Center, The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan, b)Faculty of Engineering, Osaka Institute of Technology, 16-1 Omiya 5-chome, Asahi-ku, Osaka 535 0002, Japan, c)Department of Environmental Sciences, Faculty of Science, Osaka Women's University, 2-1 Daisen-cho, Sakai, Osaka 590-0035, Japan, d)Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan)
J. Mass Spectrom. Soc. Jpn., 48(5), 323-332, 2000
Chiral recognition ability of crown ether hosts toward organic amine salt guests has been evaluated using the FAB mass spectrometry coupled with our enantiomer-labeled guest method for the total 97 sets of chiral host-guest complexations. The hosts include various chiral crown ethers containing a dimethoxyphenyl group (1-1
6) and the related derivatives (17-22) and the guests include 1-(1-naphthyl)ethylamine salt (23) and a-amino acid methyl ester salts (24-28). In the case of the a-amino ester salt guests, the chiral crown ether (1 or 2) having sterically effective phenyl substituents as chiral barriers with a less flexible backbone-structure showed relatively higher degree of chiral recognition ability among the 22 chiral host series studied. On the other hand, toward the 1-(1-naphthyl)ethylamine salt guest, the most hosts gave relatively lower chiral recognition ability except for the specific hosts (6 and 7) having certain spatial constraint toward a complexing naphthyl group.
Shigeki MATSUMURA,*a) Reiko TSUKAMOTO,b) and Kimio ISAb) (*a)Forensic Science Laboratory, Fukui Prefectural Police Headquarters, 3-17-1 Ohte, Fukui 910-8515, Japan, b)Natural Science Education Laboratory, Faculty of Education and Regional Science, Fukui University, 3-9-1 Bunkyo, Fukui 910-8507, Japan)
J. Mass Spectrom. Soc. Jpn., 48(5), 333-340, 2000
Fast atom bombardment (FAB) mass spectrometric behavior of hydrochlorides of basic compounds has been studied with the aid of collisionally activated dissociation (CAD) and metastable ion (MI) spectra. The FAB mass spectrum of guanidine hydrochloride showed the cluster ions, [n(M·HCl)+M+H]+(n=1, 2, 3
), where M and HCl are a guanidine molecule and hydrogen chloride, respectively. The FAB mass spectra of various hydrochlorides of basic compounds (M·HCl) were obtained and some compounds produced these cluster io
ns but some did not produce them. The CAD and MI spectra of the cluster ions from hydrochlorides of mono-, di-, and trimethylamine, and mono-, di-, and triethylamine were obtained in order to know the characteristics of these cluster ions. HCl loss (from [n(M·HCl)+M+H]+) ions appeared and the relationship between the HCl loss ion intensity and cluster number (n) suggests that HCl loss from the cluster ions depends on the molecular structure of compounds. The ion [M·HCl+H]+ was not observed in the FAB mass spectra, but only appeared in the CAD spectra from [(M+HCl)+M+H]+ when M was monomethylamine, dimethylamine, and monoethylamine.
Tomokazu NAKANOa) and Yoshinao WADA*a) (*a)Department of Molecular Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, 840 Murodo-cho, Izumi, Osaka 594-1101, Japan)
J. Mass Spectrom. Soc. Jpn., 48(5), 341-345, 2000
The presence of a hemoglobin mutant was suggested in a male subject who showed an apparently false level of glycated hemoglobin based on ion-exchange chromatography. Electrospray ionization mass spectrometry detected a mutant molecule with a mass of 15, 103 units, 23 units less than normal a-globin. The mutation was identified in a large tryptic peptide, aT9, of residues 62-90. Endoproteinase Asp-N digestion of carboxymethylated a-globin cleaved the region into peptides of ca. 1,000 Da, and localized the mutation to the peptide corresponding to residues 85-94. Collision-induced dissociation of the mutated peptide identified
an amino acid substitution, His
Asn, at position 89. This is a newly described mutation and the mutant was named Hb Tokyo II.
Satoko AKASHI*a) and Koji TAKIOa) (*a) Division of Biomolecular Characterization, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan)
J. Mass Spectrom. Soc. Jpn., 48(5), 346-352, 2000
This paper presents the results of electrospray ionization mass spectrometry (ESIMS) applied to an enzyme-inhibitor complex, using papain and cystatin with partly lagged N-terminus. It has been reported that the inhibitory activity of cystatin, a thiol protease inhibitor, toward papain decreases in several orders of magnitude when the N-terminal seven or eight residues are lost. In the absence of papain, multiply charged full-length cystatin was mainly observed accompanied by the signals of minor components, N-terminally truncated forms. When cystatin was mixed with equimolar quantity of papain, the relative intensity of the free full-length cystatin dramatically decreased. It might be caused by the higher binding affinity of the intact cystatin for papain than those of the truncated forms. The present study indicates the potential of ESIMS for the investigation of the structure-activity relationship without isolation of each inhibitor species carrying different level of inhibitory activity.
Tsuyoshi FUKUO, Naoko KUBOTA, Masahiro TAMURA, and Ryuichi ARAKAWA (*a)Department of Applied Chemistry, Kansai University, Yamate-cho, Suita 564-8680, Japan, b)Fuso Pharmaceutical Industry (Morinomiya, Jyoto-ku, Osaka 536-0025
, Japan) )
J. Mass Spectrom. Soc. Jpn., 48(5), 353-356, 2000
The catheter tubes of medical silicon rubber were dipped in ethanol. The effluents were fractionated by thin-layer chromatography (TLC), and their fractions were analyzed by ion trap electrospray ionization mass spectrometry (ESI-MS). The ESI mass spectra resulting from the main TLC fraction, Rf=0.5 showed that the effluents were determined to be poly(dimethyl siloxane) (8 to 20 mer) that is a main part of a silicon rubber. The spectra for the origin in TLC showed that poly(ethylene glycol) (4 to 10 mer and 14 to 18 mer) and poly-(propylene glycol) (19 to 36 mer) as an antistatic agent were identified.
Daisuke OKUMURA, Kousuke KUMONDAI, Shin-ichi YAMAGUCHI, Michisato TOYODA, Morio ISHIHARA, and Itsuo KATAKUSE (Department of Physics, Graduate School of Science, Osaka University (1-16 Machikaneyama, Toyonaka, Osaka 560-0043, Japan)
J. Mass Spectrom. Soc. Jpn., 48(5), 357-359, 2000
Generally, an ion source is supplied with high voltage to accelerate ions. However, the high voltage on the ion source makes some difficulties in applying pulse voltage or introducing samples, etc. We developed a new ion source to solve these problems. This new ion source consists of a grounded ionization region, an acceleration region and a cylinder. While the electric potential of the cylinder is varied, the electric field in the cylinder does not change and the kinetic energy of the ions in the cylinder is independent of the potential of the cylinder. After the ions formed in the ion source at the ground potential go into the cylinder at the accelerating potential, the electric potential of the cylinder is varied from the accelerating potential to the ground potential. By this method, ions keep accelerated velocity after the cylinder. To confirm this idea, we constructe
d a time-of-flight (TOF) mass spectrometer having an ion source and an analyzer, both of which are at the ground potential.
Kyoko KOJIMA,a) Minoru SAKAIRI,a) Yasuaki TAKADA,a) and Jun NAKAMURAb) (a)Central Research Laboratory, Hitachi Ltd., 1-280 Higashikoigakubo, Kokubunji, Tokyo 185-8601, Japan, b)National Research Institute of Police Science, 6-3-1 Kashiwanoha, Kashiwa, Chiba 277-0882, Japan)
J. Mass Spectrom. Soc. Jpn., 48(5), 360-362, 2000
To enable vapor detection of TNT and RDX, we have combined atmospheric pressure chemical ionization (APCI) mass spectrometry with counter-flow introduction (CFI) of sample vapors. The chemical ionization source, which enables high ionization efficiency and highly selective ionization, was attached to a quadrupole mass spectrometer. Using this modified mass spectrometer, we obtained negative mass spectra and detection chromatograms of trinitrotoluene (TNT) and 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) vapors at room temperature. The explosives detection could be done within 5 s. Our test results from this prototype system demonstrate that this technique is suitable for practical on-line explosives detection.
