Capillary Electrophoresis Interfaced with a Mass Spectrometer (CE-MS): Technical Considerations and Applicability for Biomarker Studies in Animals

Abstract

Proteomics is a growing field that has the potential to be applied to many biology-related disciplines. However, the study of the proteome has proven to be very challenging due to its high level of complexity when compared to genome and transcriptome data. In order to analyse this level of complexity, high resolution separation of peptides/proteins are needed together with high resolution analysers. Currently, liquid chromatography and capillary electrophoresis (CE) are the two most widely used separation techniques that can be coupled on-line with a mass spectrometer (MS). In CE, proteins/ peptides are separated according to their size, charge and shape leading to high resolving power. Although further progress in the area of sensitivity, throughput and proteome coverage are expected, MS-based proteomics have developed to a level at which they are habitually applied to study a wide range of biological questions. The aim of this review is to present CE-MS as a proteomic analytical platform for biomarker research that could be used in farm animal and veterinary studies. This is a MS-analytical platform that has been widely used for biomarker research in the biomedical field but its application in animal proteomic studies is relatively novel. The review will focus on introducing the CE-MS platform and the primary considerations for its application to biomarker research. Furthermore, current applications but more importantly potential application in the field of farm animals and veterinary science will be presented and discussed.

Animal board invited review: advances in proteomics for animal and food sciences

“…Furthermore, proteomic technologies are compatible with novel extraction procedures to enrich for bacterial hydrophobic outer membrane proteins expressed during infection (Nally et al , 2007 ; Crother and Nally, 2008 ). Finally, the continued development of novel proteomic approaches such as Capillary Electrophoresis-Mass Spectrometry (CE-MS) have the capability to identify panels of peptides that can be used for disease diagnosis and for differential diagnosis of the causative bacteria of the infections of the mammary gland (Mansor et al , 2013 ; Albalat et al , 2014 ). As with bovine species, a significant amount of proteomic studies have been performed on porcine species (de Almeida and Bendixen, 2012 ; Ceciliani et al , 2014 ).…”

Precise quantitation of 136 urinary proteins by LC/MRM-MS using stable isotope labeled peptides as internal standards for biomarker discovery and/or verification studies

“…As indicated by many recent articles [14][15][16][17][18][19][20][21][22][23], and extensive reviews [3,24], identification of differentially expressed proteins has commonly been achieved through iTRAQbased studies with multidimensional LC-MS/MS. Additional MSbased methods have also been developed using capillary electrophoresis [24] despite the lower mass loading capacity of the capillary columns compared to conventional LC columns [25,26]. Furthermore, CE has a volumetric limitation (low nanoliters vs. microliters in LC) that can also limit the sensitivity of MS detection if sample pre-concentration (via solid phase extraction, for instance) is not performed first.…”

Capture efficiency of dynamic pH junction focusing in capillary electrophoresis

“…The simulations were performed with the downloadable free program Simul 5 Complex on a PC platform . Mass continuity, electromigration, ionic strength, and conductivity were all considered in this program.…”

“…Due to the increased importance of MS in the past 30 years, modern MS detectors can provide CE with zeptomole detection limit along with extremely high selectivity from ultrahigh resolution and complex ion manipulation . Well‐developed ESI interface can successfully couple CE separation with MS to identify and quantify target molecules .…”