Magnetic Susceptibility to Measure Total Protein Concentration from NMR Metabolite Spectra: Demonstration on Blood Plasma
Magnetic Susceptibility to Measure Total Protein Concentration from NMR Metabolite Spectra: Demonstration on Blood Plasma
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DOI：
10.1002/mrm.25178
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发表时间：
2015-02-01
影响因子：
3.3
通讯作者：
Wijmenga, Sybren S.
中科院分区：
文献类型：
--
作者：
Jupin, Marc;Michiels, Paul J.;Wijmenga, Sybren S.
PurposeAccurate metabolite and protein quantification in blood plasma and other body fluids from one single NMR measurement, allowing for improved quantitative metabolic profiling and better assessment of metabolite-protein interactions.Theory and MethodsThe total protein concentration is derived from the common chemical-shift changescaused by protein-induced bulk magnetic susceptibility (BMS)measured on well-accessible and exchange-free metabolite resonances. These BMS shifts are simply obtained by external referencing with respect to 3-(trimethylsilyl)propionic-2,2,3,3-d4 acid, sodium salt in a coaxial insert.ResultsBased on blood-plasma data from five volunteers, the estimated accuracy of the BMS method is5% with respect and comparable to the 3.8% error of the standard colorimetric, Biuret, method. Valine, alanine, glucose, leucine, and lactate display no exchange-induced shift changes. Their well-accessible signals act as reliable probes for pure protein-induced BMS. The slopes and intercepts of their chemical-shift change versus protein concentration were derived from metabolite mixtures with (fatted) human and bovine albumin acting as blood-plasma mimics.ConclusionThe BMS method, demonstrated on blood plasma, can also be used on other samples containing sufficient protein (> 10 g/L). Also, it allows measurement of the presence and sign of exchange-induced chemical-shift changes. Magn Reson Med 73:459-468, 2015. (c) 2014 Wiley Periodicals, Inc.
