The microheterogeneity of desialylated α1-antichymotrypsin : the occurrence of two amino-terminal isoforms, one lacking a His-Pro dipeptide
ACT (α1-antichymotrypsin), a serine antiproteinase with specificity against neutrophil cathepsin G, is homologous with α1-antitrypsin, plasminogen activator inhibitor and angiotensinogen, all with known amino-terminal microheterogeneity. Here we report that the two predominant isoforms of desialylated ACT obtained on isoelectric focusing correspond to a microheterogeneity at the amino terminus of