Patent ID: 9588125
Date: 2017-03-07
CPC Classifications: C12Q,G01N

Claim:
1. A method for analyzing a protein or peptide for determining at least an amino-acid composition of a protein or a peptide, an amino-acid sequence of the protein or the peptide or quantities of amino acids in the protein or the peptide, comprising: a) a fragmentation step, in which a peptide originating from an analysis target which is either a peptide or a protein is broken down into peptide fragments by breaking peptide bonds using a broad-spectrum endopeptidase; b) a separation step, in which a mixture of the peptide fragments obtained in the fragmentation step is separated according to kinds of peptide fragments and collected in a form of fractions, each fraction containing a same kind of peptide fragment, c) a fragment composition deduction step, in which mass spectrum data are obtained by performing a mass spectrometry on each of the peptide fragments separated in the separation step and in which an amino-acid composition of each peptide fragment is deduced based on mass spectrum data; and d) a sequence deduction step, in which the amino-acid sequence of the peptide or protein is deduced, based on the amino-acid sequence of each of the peptide fragments deduced in the fragment composition deduction step, by combining different peptide fragments, the different peptide fragments include at least a first peptide fragment, a second peptide fragment, and a third peptide fragment; the first peptide fragment including a sequence pattern located in an end portion of the first peptide fragment that matches a sequence pattern located in a beginning portion of the second peptide fragment, and the second peptide fragment including a sequence pattern located in an end portion of the second peptide fragment that matches a sequence pattern located in a beginning portion of the third peptide fragment; wherein the amino-acid composition of the protein or the peptide before fragmentation, the amino-acid sequence of the protein or the peptide or the quantities of amino acids in the protein or the peptide before fragmentation is deduced by performing step (d) for each of the peptide fragments separately collected in the separation step.