Evolutionary implications of sequential homologies among members of the trypsin/a-amylase inhibitors family (CM-proteins) in wheat and barley

The N-terminal amino acid sequence of four members of the trypsin/α-amylase inhibitor family in wheat, CM1, CM2, CM16 and CM17, has been investigated for 27–29 cycles by automated sequencing procedure. None of the proteins showed inhibitory activity against trypsin or α-amylases from different sources. The N-terminal sequences of these four proteins present a high degree of homology to each other as well as to those reported for other members of the same family in wheat and barley. Such homology is higher between a given protein and a second one associated with a different genome than between that protein and any other encoded in the same genome, indicating that most of the dispersion of the corresponding multi-gene family over several chromosomes took place before the wheat/barley evolutionary branching-out