Cytoplasmic aspartate aminotransferase from pig heart muscle: Partial sequence

The primary structure of aspartate aminotransferase from pig heart muscle determined in part using a protease with specificity for lysine

“…The structure given here is essentially in agreement with that of Ovchinnikov et al [3]. However, the authors gave no indication of the data which was used to overlap their previously reported 21 partial sequences [4]. We consider it important, for this reason and due to the large size of the molecule, to confirm the correctness of the published structure and to show how the structure was derived from our earlier data.…”

Identification of the functionally important cysteinyl residue in pig heart aspartate aminotransferase

“…Comparison of our data with the published partial peptide sequence of aspartate aminotransferase [3] indicates that the functionally important cysteine residue is localized in the C-terminal part of the enzyme's polypeptide chain (tryptic fragment No. 22 in [3]).…”

“…22 in [3]). The syncatalytically reactive cysteine residue was independently and simultaneously identified by P. Christen and associates (communication at the 8th FEBS Meeting [ 1 l] and who kindly sent a preprint of a forthcoming paper) who used other procedures for labeling its SH group.…”

Location of exposed and buried cysteine residues in the polypeptide chain of aspartate aminotransferase

“…This tryptic peptide (AT-3-1) coincides with the peptide of the limited tryptic digest (residues 81-85; refs. [1,9]) and, accordingly, includes the Cys-82 residue.…”

“…This peptide (AT-2-1) corresponds to the fragment of the peptide chain (residues 42-54; refs. [1,9] ), which includes Cys-45. From fraction AT-1 ( fig.…”