ABSTRACT
ArOOCRH2O0 ArOHRCOOH
A human serum enzyme, molecular weight about
43 000 and pI 5.1, is a glycoprotein, with phenyl
acetate and paraoxon as substrates [F717]. Liver
aspirin esterase (E.C. 3.1.1.55) has an optimum at
pH 5/6.5 [C779]. Erythrocyte aspirin esterase is an intracellular cytosolic enzyme, molecular
weight 95 000. It appears to be different from
‘nonspecific’ esterases [C705]. Lens isozymes
(molecular weights 200 000 and 30 000) hydrolyze
4-methylumbelliferyl palmitate [J233]. Liver
microsomes hydrolyze p -nitrophenyl acetate,
propionate and butyrate [H465]. Plasma heroin
hydrolase is an arylesterase, optimum pH about
7.5, which also acts on p -nitrophenyl acetate and
p -nitrophenyl laurate, but not on p -nitrophenyl
phosphate [A798, G251].
