Analytical Chemistry and Spectroscopy
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
The characterization of two abnormal human haemoglobins by fast atom bombardment (FAB) mapping is presented. The first variant, called ‘R’, exhibits a tryptic FAB map identical to that of normal haemoglobin. However, using Staphylococcus protease V8, a peptide containing the carboxyl end of the β-chain exhibits a mass shift down to 300 mass units. This clearly indicates the deletion of the two last amino acids of the β-chain. The second variant, called ‘Grenoble’, is due to two different modifications of the β-chain. The location of the Pro → Ser exchange on peptide T5 is achieved by the collisionally activated dissociation mass analyzed ion kinetic energy spectra of the corresponding [MH]+ ion. The m/z value of that peptide indicated a supplementary acid → amide modification, which was located by amino acid sequencing using chemical methods. This work concludes with the necessity of using complementary methods for achieving rapid determinations of abnormal proteins with minute amounts.
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