Ambient Ionization Mass Spectrometry Measurement of Aminotransferase Activity

作者：Yan, Xin^*; Li, Xin; Zhang, Chengsen; Xu, Yang; Cooks, R. Graham^*

来源：Journal of the American Society for Mass Spectrometry, 2017, 28(6): 1175-1181.

DOI：10.1007/s13361-016-1591-x

• Clinical enzymology
• Paper spray
• Multiple reaction monitoring
• Kinetics
• Enzyme activity
• Liver Disease
• Point-of-care measurements
• Diagnostics

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.

• 出版日期2017-6
• 单位吉林大学