EVOLUTION OF AVIAN OVOMUCOIDS

Publisher Summary This chapter describes the evolution of avian ovomucoids, the preliminary amino acid sequence of Japanese quail, and the composite sequence of the region surrounding the connecting peptide between second and third domains. Limited studies were carried out on the question of whether the three domains in ovomucoids interact or are independent. The results, not yet as quantitative, suggest complete independence. The most important result is that the inhibitory activity of entire ovomucoids is the same as of their separated domains. The chapter presents the partial sequences of ovomucoid domains. The third domains show the truly amazing P 1 variability. The one with Lys inhibits trypsin. The ones with Met and Leu typically inhibit bovine chymotrypsin A, porcine chymotrypsin C, Streptomyces griseus proteinases A and B, porcine elastase and subtilisin (except for scaled quail which does not inhibit subtilisin). In addition, duck third domain, but none of the others tested, inhibits a lytic proteinase from Myxobacter.