Shimadzu Corporation

Hiroshima University

Shunsuke Izumi

Yuko Fukuyama

Koichi Tanaka

Takushi Yamamoto

Manaho Yamaguchi

One mode is a method for the structural analysis of an organic compound by MALDI mass spectrometry, including: a sample preparation process (S) which includes preparing a sample by mixing a specimen containing an organic compound to be analyzed with a predetermined matrix at a mixture ratio within a range from 1:5 to 1:5000 in molar ratio; a mass spectrometry process (S) which includes irradiating the prepared sample with a laser beam having a spot size equal to or smaller than 15 &#x3bc;m to generate ions originating from a component of the specimen in the sample, and performing a mass spectrometric analysis of the generated ions; and an analyzing process (S) which includes detecting, from a mass spectrum acquired in the mass spectrometry process, ions including product ions resulting from in-source decay, and estimating the structure of the organic compound to be analyzed based on information concerning the ions.

Method for structural analysis of organic compound

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 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.

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Higashihiroshima, Japan

Shunsuke Izumi