Tandem mass spectrometry assays of palmitoyl protein thioesterase 1 and tripeptidyl peptidase activity in dried blood spots for the detection of neuronal ceroid lipofuscinoses in newborns.

Abstract

We report new substrates for quantitative enzyme activity measurements of human palmitoyl protein thioesterase (PPT1) and tripeptidyl peptidase (TPP1) in dried blood spots from newborns using tandem mass spectrometry. Deficiencies in these enzyme activities due to inborn errors of metabolism cause neuronal ceroid lipofuscinoses. The assays use synthetic compounds that were designed to mimic the natural substrates. Incubation produces nanomole quantities of enzymatic products per a blood spot that are quantified by tandem mass spectrometry using synthetic internal standards and selected reaction monitoring. The assays utilize a minimum steps for sample workup and can be run in a duplex format for the detection of neuronal ceroid lipofuscinoses or potentially multiplexed with other mass spectrometry-based assays for newborn screening of lysosomal storage disorders.

• Authors: Mariana Barcenas, Chang Xue, Tatyana Marushchak-Vlaskin, C Ronald Scott, Michael H Gelb, František Tureček
• Journal: Analytical chemistry (Anal Chem) Vol. 86 Issue 15 Pg. 7962-8 (Aug 05 2014) ISSN: 1520-6882 [Electronic] United States
• PMID: 25019629 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Tripeptidyl-Peptidase 1
• Thiolester Hydrolases
• palmitoyl-protein thioesterase
• TPP1 protein, human

Topics

• Humans
• Infant, Newborn
• Infant, Newborn, Diseases (blood, diagnosis, enzymology)
• Neuronal Ceroid-Lipofuscinoses (blood, diagnosis, enzymology)
• Reference Standards
• Tandem Mass Spectrometry (methods)
• Thiolester Hydrolases (blood)
• Tripeptidyl-Peptidase 1