Peptidase-3 (Pep-3), dipeptidase variant in the rat homologous to mouse pep-3 (Dip-1) and human PEP-c.

Starch gel electrophoresis and histochemical staining with L-leucyl-L-tyrosine have revealed genetic variation for dipeptidase in Rattus norvegicus. The tissue distribution, substrate specificity, and heterozygous expression as a monmeric protein suggest homology of the variant peptidase to human PEP-C and mouse Pep-3 (Dip-1). We propose Peptidase-3 (Pep-3) as a name for this autosomal locus in the rat. The allele responsible for slower (less anodal) electrophoretic migration is designated Pep-3a and is characteristic of strain ACI/Pit. A faster (more anodal) electrophoretic mobility is the product of the Pep-3b allele in strain F344/Pit. Twenty-five additional inbred strains carry Pep-3a and 16 others carry Pep-3b. Wild rats trapped in Pittsburgh were polymorphic for this locus. Alleles at Pep-3 segregated independently of c (linkage group I), a (linkage group IV), RT2 and Es-1 (linkage group V), h (linkage group VI), and RTI (linkage group VIII).