<p>Due to the hydrophobic nature of integral membrane proteins (IMP) they give rise to several difficulties concerning handling and analysis, which is not the case for the most water soluble proteins. New analysis methods are needed, where the insolubility problems of the hydrophobic proteins due to aggregation and adhesion are tackled. Those problems also affect digestion performance and equipment compatibility for the analysis.</p><p>Protocols for analysis and separation specified for IMP are presented in <b>Paper I</b> and<b> III</b>.</p><p>The instrumentation used in this work was capillary electrophoresis (CE) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Both instruments are suitable for peptide/proteins analysis.</p><p>In <b>Paper I</b>, protocols for a CE separation of bacteriorhodopsin (BR) peptides as model IMP peptides are established. Also, a partially automated manufacturing procedure of a concentration MALDI-target is presented, suitable for fractions from CE. The MS analysis detected 9 out of 10 cyanogen bromide (CNBr) digested BR peptides. A novel technique for the off-line integration of CE to MALDI-MS using a closed-open-closed system is presented in <b>Paper II</b>, where the open part is a microcanal functioning as a MALDI target window. Investigation of the microcanal electro-osmotic flow (EOF) properties and band broadening characteristics was performed. A protein separation was obtained and detected with MALDI-MS analysis in the microcanal. Different protein digestion methods were evaluated using BR in <b>Paper III</b> through MALDI-MS. Several digestion methods as well as MS media were investigated alongside different MALDI matrices. For example, matrices as the hydrophobic 2,6-dihydroxyacetophenone (DHAP) and 2-Hydroxy-3-methoxybenzoic acid (2H3MBA) or 2-Hydroxy-5-methoxybenzoic acid (2H5MBA) mixed with DHB, appeared to be promising matrices for analysis of BR.</p> / <p>Med anledning av integrala membranproteiners (IMP) hydrofoba egenskaper uppstår flera svårigheter vid hantering och analys av IMP, vilket inte är fallet för vattenlösliga proteiner. Nya analysmetoder krävs, som löser löslighetsproblemen för de hydrofoba proteinerna som tex flockning och adsorbtion. Dessa problem påverkar även klyvningsgrad och kompatibilitet med analysutrustningen.</p><p>I <b>Artikel I</b> och <b>Artikel III</b> presenteras protokoll för analys och separation specifikt för IMP. Instrumenteringen som har använts i detta arbete är kapillärelektrofores (CE) och matris-assisterad laserdesorptions-joniserings-masspektrometri (MALDI-MS). Båda instrumenten är lämpade för peptid/protein analyser.</p><p>I <b>Artikel I</b>, presenteras protokoll för en CE separation av peptider från bacteriorhodopsin (BR), som användes som modellpeptider för IMP. En delvis automatiserat tillverkningsprocedur för en koncentrerande MALDI-platta, som är anpassad för CE fraktionerna beskrivs också. MS-analysen detekterade 9 av 10 BR-peptider från cyanobromid-klyvning (CNBr). En ny teknik för off line-integrering av CE till MALDI-MS genom ett slutet-öppet-slutet system presenteras i <b>Artikel II</b>, där den öppna delen är en mikrokanal som fungerar som detektionsfönster i MALDI. Undersökning av mikrokanalens egenskaper som tex det elektroosmotiska flödet (EOF) och bandbreddningen utvärderades. En proteinseparation genomfördes och detekterades med MALDI–MS i mikrokanalen. Olika proteinklyvningsmetoder för BR undersöktes i <b>Artikel</b> <b>III</b> med MALDI-MS. Flera proteinklyvningsmetoder samt MS-medier utvärderades tillsammans med olika MALDI-matriser. Den hydrofoba matrisen 2,6-dihydroxyacetophenone (DHAP) och 2-Hydroxy-3-methoxybenzoic acid (2H3MBA) eller 2-Hydroxy-5-methoxybenzoic acid (2H5MBA) blandade med DHB, visade sig exempelvis vara lovande matriser för BR-analyser.</p>

Due to the hydrophobic nature of integral membrane proteins (IMP) they give rise to several difficulties concerning handling and analysis, which is not the case for the most water soluble proteins. New analysis methods are needed, where the insolubility problems of the hydrophobic proteins due to aggregation and adhesion are tackled. Those problems also affect digestion performance and equipment compatibility for the analysis. Protocols for analysis and separation specified for IMP are presented in Paper I and III. The instrumentation used in this work was capillary electrophoresis (CE) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Both instruments are suitable for peptide/proteins analysis. In Paper I, protocols for a CE separation of bacteriorhodopsin (BR) peptides as model IMP peptides are established. Also, a partially automated manufacturing procedure of a concentration MALDI-target is presented, suitable for fractions from CE. The MS analysis detected 9 out of 10 cyanogen bromide (CNBr) digested BR peptides. A novel technique for the off-line integration of CE to MALDI-MS using a closed-open-closed system is presented in Paper II, where the open part is a microcanal functioning as a MALDI target window. Investigation of the microcanal electro-osmotic flow (EOF) properties and band broadening characteristics was performed. A protein separation was obtained and detected with MALDI-MS analysis in the microcanal. Different protein digestion methods were evaluated using BR in Paper III through MALDI-MS. Several digestion methods as well as MS media were investigated alongside different MALDI matrices. For example, matrices as the hydrophobic 2,6-dihydroxyacetophenone (DHAP) and 2-Hydroxy-3-methoxybenzoic acid (2H3MBA) or 2-Hydroxy-5-methoxybenzoic acid (2H5MBA) mixed with DHB, appeared to be promising matrices for analysis of BR. / Med anledning av integrala membranproteiners (IMP) hydrofoba egenskaper uppstår flera svårigheter vid hantering och analys av IMP, vilket inte är fallet för vattenlösliga proteiner. Nya analysmetoder krävs, som löser löslighetsproblemen för de hydrofoba proteinerna som tex flockning och adsorbtion. Dessa problem påverkar även klyvningsgrad och kompatibilitet med analysutrustningen. I Artikel I och Artikel III presenteras protokoll för analys och separation specifikt för IMP. Instrumenteringen som har använts i detta arbete är kapillärelektrofores (CE) och matris-assisterad laserdesorptions-joniserings-masspektrometri (MALDI-MS). Båda instrumenten är lämpade för peptid/protein analyser. I Artikel I, presenteras protokoll för en CE separation av peptider från bacteriorhodopsin (BR), som användes som modellpeptider för IMP. En delvis automatiserat tillverkningsprocedur för en koncentrerande MALDI-platta, som är anpassad för CE fraktionerna beskrivs också. MS-analysen detekterade 9 av 10 BR-peptider från cyanobromid-klyvning (CNBr). En ny teknik för off line-integrering av CE till MALDI-MS genom ett slutet-öppet-slutet system presenteras i Artikel II, där den öppna delen är en mikrokanal som fungerar som detektionsfönster i MALDI. Undersökning av mikrokanalens egenskaper som tex det elektroosmotiska flödet (EOF) och bandbreddningen utvärderades. En proteinseparation genomfördes och detekterades med MALDI–MS i mikrokanalen. Olika proteinklyvningsmetoder för BR undersöktes i Artikel III med MALDI-MS. Flera proteinklyvningsmetoder samt MS-medier utvärderades tillsammans med olika MALDI-matriser. Den hydrofoba matrisen 2,6-dihydroxyacetophenone (DHAP) och 2-Hydroxy-3-methoxybenzoic acid (2H3MBA) eller 2-Hydroxy-5-methoxybenzoic acid (2H5MBA) blandade med DHB, visade sig exempelvis vara lovande matriser för BR-analyser. / QC 20101109

In this thesis, improved techniques for biomolecule analysis using capillary electrophoresis (CE) and matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) and hyphenations between those have been presented.A pre-concentration method which is possible to apply in both techniques, has also been investigated. In this work the off-line MS mode has been used either in the form of fractionation (Paper I) or by incorporating the MALDI target in the CE separation system (Paper II).In Paper I, a protocol for CE-MALDI analysis of cyanogen bromide digested bacteriorhodopsin (BR) peptides as model integral membrane protein peptides were established. Also, an improved protocol for partially automated manufacturing of a concentration MALDI-target plate is presented. The design of the targets was suitable for the fractions from the CE. A novel technique for the integration of CE to MALDI-MS using a closed-open-closed system is presented in Paper II, where the open part is a micro canal functioning as a MALDI target window. A protein separation was obtained and detected with MALDI-MS analysis in the micro canal. A method has been developed for detection of monosaccharides originating from hydrolysis of a single wood fiber performed in a micro channel, with an incorporated electromigration pre-concentration step preceding CE analysis in Paper III. The pre-concentration showed to be highly complex due to the fact that several parameters are included that affecting each other. In Paper IV a protocol using enzymatic digestion, MALDI-TOF-MS and CE with laser induced fluorescence (LIF) detection for the investigation of the degree of substitution of fluorescein isothiocyanate (FITC) to bovine serum albumin (BSA), as a contact allergen model system for protein-hapten binding in the skin, is presented. The intention of a further CE-MALDI hyphenation has been considered during the work. In Paper V 2,6-dihydroxyacetophenone (DHAP) was investigated, showing promising MALDI-MS matrix properties for hydrophobic proteins and peptides. 2,5-dihydroxybenzoic acid (DHB) was undoubtedly the better matrix for the hydrophilic proteins, but its performance for the larger and hydrophobic peptides was not optimal. Consequently, DHAP can be used as a compliment matrix for improved analysis of hydrophobic analytes. / QC 20101214