Arginine metabolism by aslam matania
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Transcript of Arginine metabolism by aslam matania
WHAT IS ARGININE?
• Arginine is an α-amino acid
• In mammals, arginine is classified as a semiessential or conditionally essential amino acid, depending on the developmental stage and health status of the individual.
STRUCTURE• The amino acid
side-chain of arginine consists of a 3-carbon aliphatic straight chain, the distal end of which is capped by a complex guanidinium group
METABOLISM
• The two main sites of endogenous arginine synthesis are LIVER(where arginine is both synthesis and hydrolyzed within urea cycle)and KIDNEY CORTEX where most of the synthesized L-arginine is released into blood and transported throughout body
•Cytosolic Enzyme required are-•argininosuccinate synthetase (ASS) and argininosuccinate lyase (ASL)
•It require 2 ATP which is convert into AMP
•synthesis of arginine occurs in intestinal–renal axis
• which produce citrulline from glutamine and glutamate,
• kidney, which extract citrulline from the circulation and convert it to arginine
• The enzyme nitric oxide synthase
(three isoenzymes) cleaves the
nitrogen from the guanidino group of
arginine to form NO.
• Requires NADPH, FMN, FAD, heme &
tetrahydrobiopterin(BH4)
AGMATINE
• Agmatine:
• It is a derivative of arginine produced in
the brain by decarboxylation.
• Agmatine possesses antihypertensive
properties.
Abnormalities • Except arginase other enzyme def. in urea
cycle distrubs arginine level in the body.• Hyperargininemia inborn error in arginine
metabolism due to a defect in the enzyme arginase.
• Hypoargininemia premature occurs before the burst of cortisol production that occurs late in preg. Cortisol is req for activation of arginine synthetic enzymes
• Remedy + of cortisol to infant(premature) may improve growth and survival rate