HISTIDINE BIOTRANSFORMATION MEDIATED BY L-HISTIDINE-AMMONIA-LYASE

Galina- Borisova-,Olga- Bessonova-

doi:10.12737/2052

Abstract

Kinetics of the metabolism of the heterocyclic amino acid histidine exposed to the L-histidine ammonia-lyase enzyme has been investigated and the technology of extraction of histidine biotransformation products (urocanic acid and ammonia) from casein hydrolyzates enabling the subsequent use of these hydrolyzates as a milk protein concentrate for the production of specialized dietary products for the nutrition of histidinemia patients has been developed.

Highlights

Over 600 inherited metabolic disorders, including hereditary disorders of amino acid metabolism, have been identified to date
The disease is a congenital defect of histidine-ammonia-lyase, an enzyme that belongs to the lyase class (EC 4.3.1.3, gene HAL, 12q22-q23) and catalyzes the deamination of L-histidine to form urocanic acid and ammonia
The metabolic block leads to accumulation of large amounts of histidine and the products of its abnormal metabolism in the tissues and body fluids of the patient, this having a toxic effect on the central nervous system [8, 9, 14, 19, 24]

Summary

INTRODUCTION

Over 600 inherited metabolic disorders, including hereditary disorders of amino acid metabolism (histidinemia, phenylketonuria, tyrosinemia, alkaptonuria, and others), have been identified to date. Diseases associated with disturbed amino acid metabolism develop if the activity of an enzyme involved in the metabolism of ingested amino acids is selectively reduced. These diseases affect the central nervous system, resulting in mental retardation with motor and speech defects, impaired vision and hearing, emotional and behavioral disorders, and seizures [1, 4]. The vast majority of hereditary metabolic disorders is caused by genetic defects affecting enzymes involved in the metabolism of amino acids, carbohydrates, and lipids. Histidinemia is a hereditary disease associated with a disturbance of the metabolism of the amino acid histidine. The aim of the present work was to study histidine biotransformation in milk protein hydrolyzates treated by L-histidine-ammonia-lyase, to develop a technique for biotransformation, and to elaborate a procedure for the production of a milk protein concentrate for use in specialized dietary products

OBJECTS AND METHODS

RESULTS AND DISCUSSION

Before purification After purification