Work

Egasyn, a protein which determines the subcellular distribution of beta-glucuronidase, has esterase activity.

Year: 1985

Type: article

Abstract: The glycoprotein egasyn complexes with and stabilizes precursor beta-glucuronidase in microsomes of several mouse organs. Several observations indicate egasyn is, in addition, an esterase. Liver homogenates of egasyn-positive strains have specific electrophoretically separable esterases which are absent in egasyn-negative mice. These esterases react with anti-egasyn serum. A specific esterase was likewise complexed with immunopurified microsomal beta-glucuronidase. The esterases were, like egasyn and microsomal beta-glucuronidase, concentrated in the microsomal subcellular fraction. Egasyn which is not bound to beta-glucuronidase, which represents 80-90% of total liver egasyn, is not complexed with other liver proteins. Egasyn, therefore, specifically stabilizes beta-glucuronidase in microsomes. The esterase activity is inhibited by bis-p-nitrophenyl phosphate indicating it is a carboxyl esterase. Several possible functions of egasyn-esterase activity are discussed.

Source: Journal of Biological Chemistry

DOI: 10.1016/s0021-9258(17)36329-9

Authors: S Medda, R T Swank

Institution: Roswell Park Comprehensive Cancer Center

Language: English

Topic: Pharmacogenetics and Drug Metabolism

Subfield: Pharmacology

Field: Pharmacology, Toxicology and Pharmaceutics

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funder: National Institute of General Medical Sciences