Genetic polymorphisms of the Pmo1 and Pmo2 salivary proteins detected by the modified protein staining method

Two polymorphic proteins, Pmo1 and Pmo2, were found in human parotid saliva by modifying the protein staining method of Sung & Smithies (1969). The inheritance of each polymorphism was controlled by a dominant allele at an autosomal locus. This hypothesis was supported by studies in 50 families including 103 children. The gene frequencies were Pmo1+ = 0.308, Pmo1- = 0.692, Pmo2+ = 0.026, Pmo2- = 0.974. The Pmo1 and Pmo2 proteins reacted immunologically with antisera prepared to salivary proline-rich proteins (Pr and Gl). The isoelectric point was in excess of 8.58. These results showed that the Pmo1 and Pmo2 proteins belong to the basic proline-rich proteins in human parotid saliva.