Seiko Instruments Inc

Keiji Takamoto

Akira Tsugita

Toyoaki Uchida

Tatsuaki Ataka

Toshihiko Sakuhara

Kazuo Satake

A process is disclosed for sequencing proteins or peptides from the C-terminal end. The process comprises the steps of reacting the peptide or protein with an alkyl acid anhydride to convert the carboxy-terminal thereof into oxazolone, liberating the C-terminal amino acid by reaction with acid and alcohol or with ester, and identifying the liberated amino acid or amino acid derivative.

Method for amino acid sequencing of protein or peptide from carboxy

A protein or peptide which has an amino-terminus serine or threonine which has an acetylated alpha-amino group is allowed to react with an acid, and then allowed to react with an isothiocyanate under acidic conditions to thereby obtain a thiocarbamyl compound. Then the compound is to be analyzed using Edman degradation. Analysis can be performed with fewer operation steps and without using enzymes.

Method for sequencing of protein or peptide

A protein or peptide is treated by a vapor containing an organic acid represented by the following general formula CF.sub.3 --(CF.sub.2)n--COOH (n is zero or more integer). The resulting reaction mixture is processed by a mass spectrometer to obtain a mass spectrum to measure a mass of respective chemical species contained in the reaction mixture. Alternatively, the reaction mixture is processed by an amino acid analyzer to determine an amino acid sequence of the protein or peptide from the carboxy-terminal. According to another method, the protein or peptide is treated by an anhydride of the organic acid represented by the following general formula CF.sub.3 --(CF.sub.2)n--COOH (n is zero or more integer). The resulting reaction mixture is processed by a mass spectrometer to obtain a mass spectrum to measure a mass of respective chemical species contained in the reaction mixture to determine an amino acid sequence of the protein or peptide from the carboxy-terminal.

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Nagareyama, Japan

Keiji Takamoto