| 摘要 |
Disclosed is a method which enables semiquantitative or quantitative determination of the ratio between cysteine and formylglycine residues in a protein. The method includes (a) a step of labeling the protein (i) with a halogen-substituted carboxylic acid, (ii) with a halogen-substituted carboxylic acid amide, and (iii) with a halogen-substituted carboxylic acid and then with hydrazine, or with a halogen-substituted carboxylic acid and then by oximation, (b) a step of digesting each labeled protein to provide a corresponding mixture of peptide fragments, (c) a step of subjecting each mixture to reverse phase chromatography to separate the peptide fragments from each other to produce a chromatogram, (d) a step of comparing the produced chromatograms with each other to identify the peak corresponding to the peptide fragment that contained a cysteine residue and the peak corresponding to the peptide fragment that contained a formylglycine residue. |
