Different N-terminal forms of alpha 2-plasmin inhibitor in human plasma.
Mature alpha 2-plasmin inhibitor in human plasma has 12 more N-terminal residues than hitherto anticipated. The first residue is the methionine at position 28, downstream from the N-terminus of the pre-protein. The cDNA sequence predicts that the site cleaved upon formation of the mature inhibitor is a typical signal-peptidase recognition site. The mature inhibitor (464 residues) and the previously reported, and presumably degraded, form with N-terminal asparagine (452 residues), are present in plasma in about equal amounts. They both form a stable complex with plasmin. Recent studies on a recombinant alpha 2-plasmin inhibitor suggest that the 12 additional residues have functional implications [Sumi, Ichikawa, Nakamura, Miura and Aoki (1989) J. Biochem. 106, 703-707].
Bangert
K
K
Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark.
Johnsen
A H
AH
Christensen
U
U
Thorsen
S
S
D000595:Amino Acid Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D000979:alpha-2-Antiplasmin / Q000737:chemistry*
D000979:alpha-2-Antiplasmin