Occurrence of a pyrazine binding protein in the nasal mucosa of some vertebrates.

The presence of an olfactory protein, specific for 2-isobutyl-3-methoxypyrazine, identified in cow olfactory mucosa, has been investigated in several species of all classes of vertebrates. The methods involved measurement of specific binding with the radioactive ligand and some competitors, as well as SDS electrophoresis on the crude homogenate. The results show that such protein is present only in some families of mammals, with no clear relationship to systematic position or to natural diet. The data suggest the use of more suitable species for in vivo and in vitro studies on the function of this protein.