Plasma glycoprotein member of the serpin superfamily which inhibits TRYPSIN; NEUTROPHIL ELASTASE; and other PROTEOLYTIC ENZYMES.

Synonyms: alpha 1 Proteinase Inhibitor, alpha 1 Protease Inhibitor, alpha 1 Antiproteinase, alpha 1 Antiprotease, alpha 1-Protease Inhibitor, Inhibitor, alpha 1-Protease, alpha 1-Proteinase Inhibitor, alpha 1-Antitrypsin, Zemaira, 0, Antiprotease, alpha 1, Trypsin Inhibitor, alpha 1-Antitrypsin, alpha 1-Antiproteinase, A1PI, alpha 1 Antitrypsin, Inhibitor, alpha 1-Proteinase, 1-Antiproteinase, alpha, Prolastin, Trypsin Inhibitor, alpha 1 Antitrypsin, Serpin A1