Purines and Pyrimidines Breakdown
Nucleic Acids Metabolism

Author: Gianpiero Pescarmona
Date: 21/02/2011

Description

Purine Breakdown

Uric acid is the final product of all purine bases.

Enzymes

THE GENES

DatabaseLink
Wikigenes"":http://www.wikigenes.org/e/gene/e/34.html
GeneCards"URL":
Your Favorite Gene Sigma"URL":

CHEMICAL STRUCTURE AND IMAGES

When relevant for the function

  • Primary structure
  • Secondary structure
  • Tertiary structure
  • Quaternary structure


Protein Aminoacids Percentage
The Protein Aminoacids Percentage gives useful information on the local environment and the metabolic status of the cell (starvation, lack of essential AA, hypoxia)

Protein Aminoacids Percentage (Width 700 px)

SYNTHESIS AND TURNOVER

mRNA synthesis
protein synthesis

post-translational modifications
degradation

CELLULAR FUNCTIONS

cellular localization,
biological function

  • Enzymes
DatabaseLink
BRENDA - The Comprehensive Enzyme Information System"URL":
KEGG Pathways"URL":
Human Metabolome Database"URL":
  • Cell signaling and Ligand transport
  • Structural proteins

REGULATION

Comments
2011-02-22T18:48:02 - ELENA BANINO

Lavoro svolto da Elena Asteggiano ed Elena Banino

URIC ACID

DEFINITION

Uric acid (or urate) is a heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula C5H4N4O3.

URIC ACID FORMATION
In humans uric acid is the final oxidation (breakdown) product of purine metabolism.
Uric acid is formed primarily in the liver and excreted by the kidney into the urine.

During purine metabolism, guanosine monophosphate (GMP) is split into the base guanine and ribose. Guanine is deaminated to xanthine. Similarly, adenosine monophosphate (AMP) is deaminated by the enzyme AMP deaminase to inosine monophosphate (IMP) from which the ribose unit is removed by the enzyme xanthine oxidase to form hypoxanthine.
Xanthine, is oxidized by oxygen and xanthine oxidase with the production of hydrogen peroxide and uric acid. This last reaction is irreversible.
In man, the urate is excreted and the hydrogen peroxide is degraded by catalase. Xanthine oxidase is present in significant concentration only in liver and intestine. The pathway to the nucleosides, possibly to the free bases, is present in many tissues.

Biochemical pathway of purine metabolism.
AMP = adenosine monophosphate, APRT = adenine phosphoribosyltransferase, GMP = guanosine monophosphate, HGPRT = hypoxanthine-guanine phosphoribosyltransferase, IMP = inosine monophosphate, NP = nucleoside phosphorylase, PPriboseP = 5-phosphorylribose-1-pyrophosphate.

Database LINK
KEGG URL
NetBiochem URL
What is life URL
Wikipedia URL

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