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Title: Structural and Biochemical Characterization of Human Adenylosuccinate Lyase (ADSL) and the R303C ADSL Deficiency-Associated Mutation

Adenylosuccinate lyase (ADSL) deficiency is a rare autosomal recessive disorder, which causes a defect in purine metabolism resulting in neurological and physiological symptoms. ADSL executes two nonsequential steps in the de novo synthesis of AMP: the conversion of phosphoribosylsuccinyl-aminoimidazole carboxamide (SAICAR) to phosphoribosylaminoimidazole carboxamide, which occurs in the de novo synthesis of IMP, and the conversion of adenylosuccinate to AMP, which occurs in the de novo synthesis of AMP and also in the purine nucleotide cycle, using the same active site. Mutation of ADSL's arginine 303 to a cysteine is known to lead to ADSL deficiency. Interestingly, unlike other mutations leading to ADSL deficiency, the R303C mutation has been suggested to more significantly affect the enzyme's ability to catalyze the conversion of succinyladenosine monophosphate than that of SAICAR to their respective products. To better understand the causation of disease due to the R303C mutation, as well as to gain insights into why the R303C mutation potentially has a disproportional decrease in activity toward its substrates, the wild type (WT) and the R303C mutant of ADSL were investigated enzymatically and thermodynamically. Additionally, the X-ray structures of ADSL in its apo form as well as with the R303C mutation were elucidated, providingmore » insight into ADSL's cooperativity. By utilizing this information, a model for the interaction between ADSL and SAICAR is proposed.« less
Authors:
; ; ; ; ; ; ;  [1]
  1. (Denver)
Publication Date:
OSTI Identifier:
1050757
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemistry-US; Journal Volume: 51; Journal Issue: (33) ; 08, 2012
Research Org:
Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
Sponsoring Org:
OTHERUNIVERSITY
Country of Publication:
United States
Language:
ENGLISH
Subject:
59 BASIC BIOLOGICAL SCIENCES; 60 APPLIED LIFE SCIENCES; AMP; ARGININE; CONVERSION; CYSTEINE; DEFECTS; DISEASES; ENZYMES; INTERACTIONS; LYASES; METABOLISM; MUTANTS; MUTATIONS; NUCLEOTIDES; PURINES; SUBSTRATES; SYMPTOMS; SYNTHESIS