Ambient Ionization Mass Spectrometry Measurement of Aminotransferase Activity.
Xin YanXin LiChengsen ZhangYang XuR Graham CooksPublished in: Journal of the American Society for Mass Spectrometry (2017)
A change in enzyme activity has been used as a clinical biomarker for diagnosis and is useful in evaluating patient prognosis. Current laboratory measurements of enzyme activity involve multi-step derivatization of the reaction products followed by quantitative analysis of these derivatives. This study simplified the reaction systems by using only the target enzymatic reaction and directly detecting its product. A protocol using paper spray mass spectrometry for identifying and quantifying the reaction product has been developed. Evaluation of the activity of aspartate aminotransferase (AST) was chosen as a proof-of-principle. The volume of sample needed is greatly reduced compared with the traditional method. Paper spray has a desalting effect that avoids sprayer clogging problems seen when examining serum samples by nanoESI. This very simple method does not require sample pretreatment and additional derivatization reactions, yet it gives high quality kinetic data, excellent limits of detection (60 ppb from serum), and coefficients of variation <10% in quantitation. Graphical Abstract ᅟ.
Keyphrases
- mass spectrometry
- liquid chromatography
- gas chromatography
- high performance liquid chromatography
- tandem mass spectrometry
- ms ms
- liquid chromatography tandem mass spectrometry
- high resolution mass spectrometry
- high resolution
- simultaneous determination
- solid phase extraction
- ultra high performance liquid chromatography
- gas chromatography mass spectrometry
- air pollution
- capillary electrophoresis
- mental health
- particulate matter
- hydrogen peroxide
- electron transfer
- case report
- nitric oxide
- sensitive detection
- real time pcr