Bioanalysis using capillary electrophoresis and mass spectrometry

Time: Thu 2019-10-24 10.00

Location: sal F3, Lindstedtsvägen 26, Stockholm (English)

Subject area: Chemistry

Doctoral student: Leila Josefsson , Skolan för kemi, bioteknologi och hälsa (CBH)

Opponent: Professor Ulrika Nilsson,

Supervisor: Professor Åsa Emmer, Kemi, Tillämpad fysikalisk kemi


The sequencing of the genome of various species, including the human species, have led to increased understanding about how a protein structure is generated, and how specific structures are related to the proteins’ functionality. In paper I and II of this thesis, the folding of proteins in vitro to form hierarchical nanostructures, which in vivo often have a pathological effect, have been studied. Protein isolates from soybean and potato, that are byproducts from oil and starch production, respectively, were used as a starting material for protein nanofibril (PNF) formation, and mass spectrometry was used to identify the building blocks that are included in the formed PNF. The five peptides identified in soybean PNF and the six peptides identified in potato PNF originated from the major seed storage proteins for the respective crop.

The use of ionic liquids has increased for improvement of the performance of different separation techniques due to their adjustable properties, and good solvating ability. In paper III, an ionic liquid and water mixture was used as background electrolyte in capillary electrophoresis for protein separation. The system showed high reproducibility at basic conditions, and could potentially be used for routine control analysis.

Many diseases and injuries require clinical diagnosis techniques e.g. ultrasound imaging, to be detected, and for the physician to be able to decide the correct therapy. To increase the resolution of such imaging techniques, contrast agents can be used. In paper IV-VI, a newly developed contrast agent consisting of air-filled microbubbles stabilized with a shell of polyvinyl alcohol (PVA-MBs) was studied. Development of a capillary electrophoretic method for analysis of the PVA-MBs with the intentions to be used for clinical diagnosis is performed, where different detectors such as a UV detector, a UV area imaging detector and an in-house constructed microscope are used to increase the sensitivity of detection for the PVA-MBs. The developed method could be used for quantification of the contrast agent, since individual PVA-MBs were visible using the imaging detectors. Findings regarding the mobility of the PVA-MBs in human blood plasma and in water implies that a protein corona was formed around the MBs.