Assessment of differences in the conformational flexibility of hepatitis B virus core-antigen and e-antigen by hydrogen deuterium exchange-mass spectrometry.

Hepatitis B virus core-antigen (capsid protein) and e-antigen (an immune regulator) have almost complete sequence identity, yet the dimeric proteins (termed Cp149d and Cp(-10)149d , respectively) adopt quite distinct quaternary structures. Here we use hydrogen deuterium exchange-mass spectrometry (HDX-MS) to study their structural properties. We detect many regions that differ substantially in their HDX dynamics.

Sizing up large protein complexes by electrospray ionisation-based electrophoretic mobility and native mass spectrometry: morphology selective binding of Fabs to hepatitis B virus capsids.

The capsid of hepatitis B virus (HBV) is a major viral antigen and important diagnostic indicator. HBV capsids have prominent protrusions ('spikes') on their surface and are unique in having either T = 3 or T = 4 icosahedral symmetry. Mouse monoclonal and also human polyclonal antibodies bind either near the spike apices (historically the 'α-determinant') or in the 'floor' regions between them (the 'β-determinant').

Epitope-distal effects accompany the binding of two distinct antibodies to hepatitis B virus capsids.

Infection of humans by hepatitis B virus (HBV) induces the copious production of antibodies directed against the capsid protein (Cp). A large variety of anticapsid antibodies have been identified that differ in their epitopes. These data, and the status of the capsid as a major clinical antigen, motivate studies to achieve a more detailed understanding of their interactions.

Structure, stability and dynamics of norovirus P domain derived protein complexes studied by native mass spectrometry.

Expression of the protruding (P) domain of the norovirus capsid protein, in vitro, results in the formation of P dimers and larger oligomers, 12-mer and 24-mer P particles. All these P complexes retain the authentic antigenicity and carbohydrate-binding function of the norovirus capsid. They have been used as tools to study norovirus-host interactions, and the 24-mer P particle has been proposed as a vaccine and vaccine platform against norovirus and other pathogens.

Transcriptome and proteome analysis of osteocytes treated with nitrogen-containing bisphosphonates.

We combined high-throughput screening of differential mRNAs with mass spectrometric characterization of proteins obtained from osteocytes untreated and treated with Risedronate. Microarray analysis revealed, upon treatment, a marked upregulation of messengers encoding zinc-proteins. MS analysis identified 84 proteins in the osteocytes proteome map.

Offline and online liquid chromatography mass spectrometry in quantitative proteomics.

Hyphenation with liquid chromatography has become indispensable in mass spectrometry-based proteomics. Sample complexity together with the large variations in dynamic range can be only tackled using techniques that isolate and/or concentrate individual components prior to mass spectrometric analysis. In this review the most recent developments in micro/nanoliquid chromatography interfaced with MALDI and electrospray ionisation are discussed.

Development of novel guanidino-labelling derivatisation (GLaD) reagents for liquid chromatography/matrix-assisted laser desorption/ionisation analysis.

A new generation of guanidino-labelling (GLaD) reagents were developed for quantitative proteomics using offline microcapillary liquid chromatography (LC) matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS). In order to reduce the unwanted overlapping between the isotopic envelopes of the two differentially labelled peptide ions, a novel synthetic route was described for production of both (13)C- and (15)N-containing isotopomers of N,O-dimethylisourea. The use of these types of isotopes has no deleterious effect on the retention times of both differentially labelled peptides during offline microbore reversed-phase LC.

Off-line liquid chromatography-MALDI by with various matrices and tandem mass spectrometry for analysis of glycated human serum albumin tryptic peptides.

Advanced glycation end-product (AGE)/peptides, arising from in vivo digestion of glycated proteins, are biologically important compounds, due to their reactivity against circulating and tissue proteins. For information on their possible structure, in vitro glycation of HSA and its further enzymatic digestion were performed. The resulting digestion product mixture was analysed directly by MALDI MS with various matrices [2,5-dihydroxy benzoic acid (DHB) and alpha-cyano-4-hydroxy cinnamic acid (CHCA)].

Relative quantification of tau-related peptides using guanidino-labeling derivatization (GLaD) with online-LC on a hybrid ion trap (IT) time-of-flight (ToF) mass spectrometer.

Development of a quantification method based on isotopic variants of O-methyl isourea (OMIU) in conjunction with reversed-phase (RP) liquid chromatography (LC) electrospray mass spectrometry is described for determining the relative quantification of tau-related peptides Ac-VQIVXK-NH2. Extracted ion chromatograms of the mass spectrometric data derived from online microcapillary LC separation identifies the retention times of the isotopically derivatized peptides together with their ion abundances. Data-dependent MSMS analysis of both derivatized variants of the same peptide provides a complementary method for identification and resolution between isobaric species.

Comprehensive analysis of glycated human serum albumin tryptic peptides by off-line liquid chromatography followed by MALDI analysis on a time-of-flight/curved field reflectron tandem mass spectrometer.

Glycated peptides arising from in vivo digestion of glycated proteins, usually called advanced glycation end (AGE) product peptides, are biologically relevant compounds due to their reactivity towards circulating and tissue proteins. To investigate their structures, in vitro glycation of human serum albumin (HSA) has been performed and followed by enzymatic digestion. Using different MALDI based approaches the digestion products obtained have been compared with those arising from enzymatic digestion of the protein.