Turkey serum trypsin inhibitors: description and characterization.

1. Turkey serum trypsin inhibitors were studied on whole and chromatographically fractionated normal turkey serum using both quantitative (trypsin inhibitory capacity measurement) and qualitative (antitryptic activity detection methods) determinations, coupled to electrophoretic and isoelectrophoretic studies. 2. Five proteins with trypsin inhibitory activity were described, the most important ones being alpha 2 and beta-globulins with a multibanded pattern revealed by isoelectric focusing. 3. Trypsin inhibitory capacity assays, performed on individual sera, as well as isoelectric focusing studies, failed to find any quantitative and/or qualitative deficiency of these antiproteases. 4. Evidence is given that round heart disease in turkeys is not related to serum trypsin inhibitor deficiency.