Isotopic labelling of peptides and isotope ratio analysis using LC-ICP-MS: a preliminary study.
Bradykinin and substance P have been derivatised with cyclic diethylenetriaminepentaacetic anhydride (cDTPA) and subsequently labelled with natural and isotopically enriched Eu(3+). This enabled the detection and relative quantitation of the peptides using element-selective detection by high-performance liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS). Relative quantitation was achieved by differentially labelling two peptide sources, after derivatisation with cDTPA, using natural and enriched (151)Eu respectively. The (151)Eu:(153)Eu isotope ratio was measured and used to calculate the original peptide ratio. The measured ratios came within 5.2% of the known ratio. Derivatisation and chelation reactions were additionally confirmed using LC-ESI-MS.
Patel
Pritesh
P
University of Plymouth, Speciation and Environmental Analysis Research Group, School of Earth, Ocean and Environmental Sciences, Drake Circus, Plymouth, PL4 8AA, UK.
Jones
Phil
P
Handy
Richard
R
Harrington
Chris
C
Marshall
Peter
P
Evans
E Hywel
EH
D001920:Bradykinin / Q000032:analysis* / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D005063:Europium / Q000737:chemistry; D007554:Isotopes / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D013373:Substance P / Q000032:analysis* / Q000737:chemistry*
D007554:Isotopes; D013373:Substance P; D005063:Europium; D001920:Bradykinin