Related Experiment Video
Updated: Jun 21, 2026

Preparation and In Vivo Use of an Activity-based Probe for N-acylethanolamine Acid Amidase
Published on: November 23, 2016
Rat serum carboxylesterase partly hydrolyses gamma-butyrobetaine esters
Lida Bagdoniene1, Danute Labeikyte, Ivars Kalviņs
1Department of Biochemistry and Biophysics, Vilnius University, Vilnius, Lithuania.
Abstract:
Although described some time ago, gamma-butyrobetaine esters and related compounds have not gained much attention from researchers, and their physiological function remains obscure. Formerly we detected GBB-esterase enzymatic activity in rat blood serum using phenylated gamma-butyrobetaine as an artificial substrate of the enzyme and HPLC. The aim of the present work was to develop an assay that would enable spectrophotometric or colorimetric determination of the reaction products of GBB-esterase activity and to reveal individual proteins performing GBB-esterase activity in rat blood serum. For this purpose gamma-butyrobetaine 1-naphthyl ester was synthesised. Hydrolysis of this ester releases 1-naphthol, which increases the optical absorbance at 322 nm. We have shown that the enzymatic hydrolysis of GBB 1-naphthyl ester to 1-naphthol in rat blood serum is due to GBB-esterase activity. An attempt was done to purify the enzyme from rat blood serum. By combining DEAE Sepharose at pH 4.2 and affinity chromatography with procainamide we achieved a 68-fold enrichment of GBB-esterase activity in our preparations. Separation of fraction proteins in 2D protein electrophoresis with following mass-spectrometry indicated that GBB esterase activity in rat blood serum is performed in part by carboxylesterase.
Related Concept Videos
Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
Esters to Carboxylic Acids: Saponification
The reaction requires a base in stoichiometric amounts, which participates in the reaction and is not regenerated later. So, the base acts as a...
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Carboxylic Acids to Esters: Acid-Catalyzed (Fischer) Esterification Mechanism
Carboxylic Acids to Esters: Acid-Catalyzed (Fischer) Esterification Overview

