TRYPTIC PEPTIDE-MAPPING OF SEQUENCE-299-585 OF HUMAN SERUM-ALBUMIN BYHIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY AND FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRY

The determination of the tryptic peptide mapping of sequence 299-585 ( cyanogen bromide fragment A) of human serum albumin (HSA) by chemical and enzymatic cleavages and combined use of HPLC and FAB-MS is describ ed. Reduction and carboxymethylation of A gave four subfragments which were separated by HPLC and digested with trypsin. Tryptic fragments w ere separated by HPLC and identified by FAB-MS. A total coverage of ab out 95% of the entire sequence was obtained. Tryptic fragments not ide ntified include mostly single amino acids and very hydrophilic peptide s which were absent in the chromatograms. The high reproducibility of the experiments and the satisfactory yield of the tryptic fragments id entified demonstrate the great potential of the combined use of HPLC s eparation and FAB-MS analysis for the structural investigation of HSA.