Summary
Normal mouse serum is separated electrophoretically into seven protein bands and four esterase zones designated ρ, albumin, fast α2 and α2-β1. All but albumin are associated with lipoproteins. These zones correspond on immunoelectrophoretic analysis with six precipitin lines that retain esterase activity after antigen-antibody precipitation: the ρ- and slow lipoproteins, albumin and three α2-globulins. The serum cholinesterase is associated with the α2-β1-lipoprotein and is completely removed by chloroform extraction.
Mouse serum albumin is separated by CM-and DEAE-cellulose column chromatography into two immunologically identical fractions one of which lacks the ability to hydrolyze carboxylic esters. This phenomenon represents and example of the molecular heterogeneity of mouse serum albumin.
Normal mouse urine contains two esterases of α1 and β2 mobility, the latter probably of renal origin. Normal mouse urinary albumin, unlike serum albumin, has no esterase activity.