<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>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.</p></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.

Rat Serum Carboxylesterase Partly Hydrolyses Gamma-Butyrobetaine Esters

Department of Biochemistry and Biophysics, Vilnius University, Vilnius, Lithuania

Latvian Institute of Organic Synthesis, Riga, Latvia

Department of Developmental Biology, Institute of Biochemistry, Vilnius, Lithuania

Archives of Industrial Hygiene and Toxicology

{"article-title":"Rat Serum Carboxylesterase Partly Hydrolyses Gamma-Butyrobetaine Esters"}

Although described some time ago, gamma-butyrobetaine esters and related compounds have not gained much attention from researchers, and their physiological...

Rat Serum Carboxylesterase Partly Hydrolyses Gamma-Butyrobetaine Esters

Published Online: Jul 06, 2009

Page range: 147 - 156

DOI: https://doi.org/10.2478/10004-1254-60-2009-1915

Keywords
1-naphtol, 2D electrophoresis, colorimetry, HPLC, spectrophotometry

This content is open access.

Rat Serum Carboxylesterase Partly Hydrolyses Gamma-Butyrobetaine Esters

Published Online: Jul 06, 2009

Page range: 147 - 156

DOI: https://doi.org/10.2478/10004-1254-60-2009-1915

Keywords1-naphtol, 2D electrophoresis, colorimetry, HPLC, spectrophotometry

This content is open access.

Keywords
1-naphtol, 2D electrophoresis, colorimetry, HPLC, spectrophotometry