Thioredoxin. 5. Amino Acid Sequences of the Tryptic Peptides of Peptide A.

Tryptic digestion of peptide A, the C-terminal fragment of thioredoxin, obtained by cyanogen bromide cleavage, resulted in the isolation of nine peptides. The complete amino acid sequence of each was determined, and the N-terminal and C-terminal fragments of peptide A were identified. Together the nine tryptic peptides accounted for all 71 residues of peptide A. Hydrazinolysis and studies with carboxypeptidase A established -Asn-Leu-Ala to be the C-terminal sequence of peptide A and of thioredoxin. [ABSTRACT FROM AUTHOR]