Document Detail


Tandem mass spectrometry for the direct assay of lysosomal enzymes in dried blood spots: application to screening newborns for mucopolysaccharidosis II (Hunter Syndrome).
MedLine Citation:
PMID:  21192662     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We have developed a tandem mass spectrometry based assay of iduronate-2-sulfatase (IdS) activity for the neonatal detection of mucopolysaccharidosis II (MPS-II, Hunter Syndrome). The assay uses a newly designed synthetic substrate (IdS-S) consisting of α-L-iduronate-2-sulfate, which is glycosidically conjugated to a coumarin and a linker containing a tert-butyloxycarbamido group. A short synthesis of the substrate has been developed that has the potential of being scaled to multigram quantities. Sulfate hydrolysis of IdS-S by IdS found within a 3 mm dried blood spot specifically produces a nonsulfated product (IdS-P) which is detected by electrospray tandem mass spectrometry and quantified using a deuterium-labeled internal standard, both carried out in positive ion mode. Analysis of DBS from 75 random human newborns showed IdS activities in the range of 4.8-16.2 (mean 9.1) μmol/(h L of blood), which were clearly distinguished from the activities measured for 14 MPS-II patients at 0.17-0.52 (mean 0.29) μmol/(h L of blood). The assay shows low blank activity, 0.15 ± 0.03 μmol/(h L of blood). The within-assay coefficient of variation (CV) was 3.1% while the interassay CV was 15%.
Authors:
Brian J Wolfe; Sophie Blanchard; Martin Sadilek; C Ronald Scott; Frantisek Turecek; Michael H Gelb
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2010-12-30
Journal Detail:
Title:  Analytical chemistry     Volume:  83     ISSN:  1520-6882     ISO Abbreviation:  Anal. Chem.     Publication Date:  2011 Feb 
Date Detail:
Created Date:  2011-01-31     Completed Date:  2011-05-17     Revised Date:  2012-05-30    
Medline Journal Info:
Nlm Unique ID:  0370536     Medline TA:  Anal Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1152-6     Citation Subset:  IM    
Affiliation:
Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
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MeSH Terms
Descriptor/Qualifier:
Blood Specimen Collection
Humans
Infant, Newborn
Lysosomes / enzymology*
Molecular Structure
Mucopolysaccharidosis II / blood*,  diagnosis*,  enzymology
Neonatal Screening / methods*
Tandem Mass Spectrometry / methods*
Grant Support
ID/Acronym/Agency:
R01 DK067859/DK/NIDDK NIH HHS; R01 DK067859/DK/NIDDK NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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