Isolation and characterization of α-1-antitrypsin from rhesus-monkey serum

Abstract

A simple, relatively gentle, procedure for isolation of rhesus-monkey alpha-1-antitrypsis from serum is described. The method consists of chromatographic separation of the fraction precipitated by 50-75%-satd. (NH4)2SO4 from pooled monkey serum on DEAE-cellulose followed by affinity chromatography on Sepharose-bound concanavalin A. Approx. 30% of the trypsin-inhibitory activity present in the original serum was recovered when alpha-1-antitrypsin was reconstituted with physiological saline (0.85% NaCl). Pure alpha-1-antitrypsin exhibitied a single band on sodium docecyl sulphate/polyacrylamide-gel electrophoresis, with an estimated mol.wt. of 60000 and four bands in acid/starch-gel electrophoresis. The acid/starch-gel-electrophoretic pattern and mobility of isolated material were identical with those of the alpha-1-antitrypsin bands in the original serum sample. The most rapdily migrating bands resembled the pattern and mobility for the normal human phenotype PiM in 28 monkeys. A starch strip from the acid/starch-gel-electrophoresis as the origin for antigen-antibody electrophoresis was used to examine alpha-1-antitrypsin for microheterogeneity; no evidence for microheterogeneity was observed in samples from 18 monkeys. In addition, isolated alpha-1-antitrypsin exhibited a single arc when subjected to immunoelectrophoresis. Amino acid and carbohydrate compositions of isolated monkey alpha-1-antitrypsin were similar to those of human alpha-1-antitrypsin.