Shimadzu Corporation

Hiroshima University

Osaka Prefectural Hospital Organization

Yuko Fukuyama

Koichi Tanaka

Shunsuke Izumi

Hiroto Tamura

Teruyo Kato

Yoshinao Wada

Yuzo Yamazaki

Tadayuki Iwase

Yoshinobu Manome

Yoshimitsu Mizunoe

Kouki Fujioka

A method for analyzing a microorganism including an identification step for determining which ofandwhich are two serotypes ofbacteria is contained in a sample which contains eitheror, based on the presence or absence of a peak (or peaks) at a predetermined mass-to-charge ratio (or ratios) in a mass spectrum obtained by a mass spectrometric analysis of the sample, or a method for analyzing a microorganism including an identification step for determining which ofandwhich are three serotypes ofbacteria is contained in a sample which containsor, based on the presence or absence of a peak (or peaks) at a predetermined mass-to-charge ratio (or ratios) in a mass spectrum obtained by a mass spectrometric analysis of the sample, or a method for analyzing a microorganism including an identification step for determining which of Schwarzengrund and Montevideo which are two serotypes ofbacteria is contained in a sample which contains either Schwarzengrund or Montevideo, based on the presence or absence of a peak (or peaks) at a predetermined mass-to-charge ratio (or ratios) in a mass spectrum obtained by a mass spectrometric analysis of the sample.

Method for analyzing microorganism

[OBJECT] To enable accurate identification of a specific serotype ofbacteria in a method for analyzing a microorganism using a MALDI-MS. [MEANS FOR SOLVING PROBLEM] The present invention is a method for analyzing a microorganism including an identification step for determining which of Abony and Pakistan which are two serotypes ofbacteria is contained in a sample which contains either Abony or Pakistan, based on the presence or absence of a peak (or peaks) at a predetermined mass-to-charge ratio (or ratios) in a mass spectrum obtained by a mass spectrometric analysis of the sample, or a method for analyzing a microorganism including an identification step for determining which of Minnesota. Infantis and Brandenburg which are three serotypes ofbacteria is contained in a sample which contains Minnesota. Infantis or Brandenburg, based on the presence or absence of a peak (or peaks) at a predetermined mass-to-charge ratio (or ratios) in a mass spectrum obtained by a mass spectrometric analysis of the sample, or a method for analyzing a microorganism including an identification step for determining which of Schwarzengrund and Montevideo which are two serotypes ofbacteria is contained in a sample which contains either Schwarzengrund or Montevideo, based on the presence or absence of a peak (or peaks) at a predetermined mass-to-charge ratio (or ratios) in a mass spectrum obtained by a mass spectrometric analysis of the sample.

In an analysis method of the present invention, a compound represented by the following formula (I) as a matrix is mixed into an analysis target sample and the mixture is subjected to matrix-assisted laser desorption ionization mass spectrometry. In the formula (I), R is an alkyl group having 3-11 carbon atoms. The analysis target sample is a substance for which whether or not &#x3b2;-lactamase is contained is to be determined. Analysis targets include, for example, bacteria and an extract from bacteria. 

Analysis method and &#x3b2;-lactam antibiotic resistance evaluation method

In a method for analyzing a microorganism using a matrix assisted laser desorption/ionization mass spectrometer, a matrix-and-additive mixture solution prepared by mixing one or both of an alkylphosphonic acid and a surfactant with a matrix substance is used for matrix assisted laser desorption/ionization. Either an alkylphosphonic acid or a surfactant, or both of them are used as matrix additives and are mixed with the matrix substance beforehand to prepare a matrix-and-additive mixture solution. After a solution which contains a microorganism to be analyzed has been dropped onto a sample plate, the matrix-and-additive mixture solution is dropped onto that solution and dried to form a mixed crystal which contains both the constituents of the microorganism and the matrix substance. This crystal is used as a sample for MALDI-MS analysis. The sensitivity of analysis is thereby improved, without increasing the amount of time and labor required for sample preparation.

Method for analyzing microorganisms

The present invention provides a method for specifically cleaving a C&#x3b1;-C bond of a peptide backbone and/or a side chain of a protein and a peptide, and a method for determining amino acid sequences of protein and peptide. A method for specifically cleaving a C&#x3b1;-C bond of a peptide backbone and/or a side chain bond of a protein or a peptide, comprising irradiating a protein or a peptide with laser light in the presence of at least one hydroxynitrobenzoic acid selected from the group consisting of 3-hydroxy-2-nitrobenzoic acid, 4-hydroxy-3-nitrobenzoic acid, 5-hydroxy-2-nitrobenzoic acid, 3-hydroxy-5-nitrobenzoic acid, and 4-hydroxy-2-nitrobenzoic acid. A method for determining an amino acid sequence of a protein or a peptide, comprising irradiating a protein or a peptide with laser light in the presence of the above specific hydroxynitrobenzoic acid to specifically cleave a C&#x3b1;-C bond of a peptide backbone and/or a side chain bond, and analyzing generated fragment ions by mass spectrometry.

Method for specific cleavage of C alpha-C bond and side chain of protein and peptide, and method for determining amino acid sequence

The present invention provides a mass spectrometry method using a mixed matrix, capable of easily and efficiently improving the ionization efficiency in mass spectrometry for peptides having a wide range of degrees of hydrophobicity (from hydrophilic to hydrophobic). A MALDI mass spectrometry method for analyzing a sample using as a mixed matrix, 2,4,6-trihydroxyalkylphenone represented by the following general formula (I): wherein R represents an alkyl group having 3 to 12 carbon atoms, and a matrix (II) for mass spectrometry that is more hydrophilic than 2,4,6-trihydroxyalkylphenone represented by the formula (I) wherein R is an alkyl group having 3 carbon atoms.

Mass spectrometry method using mixed matrix

The present invention provides a mass spectrometry method that can achieve analysis with high sensitivity using a matrix additive capable of improving ionization efficiency in mass spectrometry. A mass spectrometry method comprising the steps of: forming a mixed crystal for mass spectrometry on a target plate for mass spectrometry, the mixed crystal comprising a sample to be analyzed, a matrix, and a matrix additive selected from the group consisting of a 2,5-dihydroxybenzoate and a 3,5-dihydroxybenzoate that are represented by the following formula (I): where R represents an alkyl group having 4 to 14 carbon atoms; and irradiating the mixed crystal with laser to detect the sample to be analyzed.

MALDI analysis of hydrophobic compounds using 2(3),5-dihydoxybenzoate with a long alkyl chain as an additive to MALDI matrix

The present invention provides a mass spectrometry method using a matrix that is capable of easily and efficiently improving ionization efficiency in mass spectrometry without modifying a molecule to be analyzed, and a matrix for mass spectrometry. A mass spectrometry method using, as a matrix, a 2,4,6-trihydroxyalkylphenone represented by the following general formula (I): where R is an alkyl group having 4 to 12 carbon atoms. The mass spectrometry method as described above, wherein an analysis object is a hydrophobic compound, particularly, a hydrophobic peptide.

Mass spectrometry method using matrix

The present invention provides a method for mass spectrometry of phosphorylated peptides or sugar chains, which suppresses the desorption of an unstable site during ionization and achieves high sensitivity (i.e., detects molecular-related ions at a high ionic strength and at a relatively higher ionic strength than other ion species derived from the desorption of an unstable site). A method for mass spectrometry of phosphorylated peptides or sugar chains, the method comprising using, as a liquid matrix, an ionic liquid comprising a 3-aminoquinoline ion and a p-coumaric acid ion. The liquid matrix comprises 3-aminoquinoline and p-coumaric acid, for example, in a molar ratio of 5:1 to 20:1. Ammonium phosphate may be used as an additive.

Mass spectrometry method of phosphorylated peptides and sugar chains

The present invention provides a simplified method for analyzing a structure of glycoprotein capable of conducting a peptide sequence analysis, a sugar chain sequence analysis, and an analysis of a sugar chain binding site accurately and rapidly using a mass spectrometer.

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Kyoto, Japan

Yuko Fukuyama