Pepsinogen-like immunoreactivity among vertebrates: occurrence of common antigenicity to an anti-chicken pepsinogen antiserum in stomach gland cells of vertebrates

Abstract

Stomachs of 14 species selected from five classes of vertebrate were surveyed concerning the reactivity to an anti-adult chicken pepsinogen antiserum (anti-ACPg) with indirect immunofluorescence method. Gland cells of all these stomachs showed reactivity to the antiserum. Crude extract of stomachs from five representatives of mammals, birds, amphibians and fish showed peptic activity (at pH 2.2) of which 70-90% were pepstatin-sensitive. Zymogram and immunoblotting of crude extract revealed that the anti-ACPg-reactive proteins have peptic activity. Molecular weights of anti-ACPg-reactive proteins determined by immunoblotting coincided with the values of purified pepsinogens previously reported for these animals. These results indicate that pepsinogens have been conserved well during vertebrate evolution.