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Electrospray-ionization Mass Spectrometry (electrospray-ionization + mass_spectrometry)

Distribution by Scientific Domains
Chemistry60%

Selected Abstracts

Electrospray-ionization mass spectrometry as a tool for fast screening of protein structural properties

BIOTECHNOLOGY JOURNAL, Issue 1 2009
Rita Grandori
Abstract Since the early 1990s, electrospray-ionization mass spectrometry (ESI-MS) has encountered growing interest as a complementary tool to established biochemical and biophysical methods for investigating protein structure and conformation. Nowadays, applications of ESI-MS to protein investigation span from the area of analytical biochemistry to that of structural biology. This review focuses on applications of this technique to the analysis of protein conformational properties and molecular interactions, underscoring their possible relevance for molecular biotechnology, although representing a still very young field. An introductive section presents the major issues related to theoretical and technical aspects of ESI-MS under non-denaturing conditions. Examples from our work and from the literature illustrate which kind of information can be obtained concerning key issues in biotechnology such as stability and aggregation of proteins under both near-native and challenging conditions, and interactions with other proteins, ligands and cofactors. [source]

Reduction of [(C5Me5)2Mo2O5] and [(C5Me5)2Mo2O4] in Methanol/Water/Trifluoroacetate Solutions Investigated by Combined On-Line Electrochemistry/Electrospray-Ionization Mass Spectrometry

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 12 2003
Jenny Gun
Abstract Complexes [Cp*2Mo2O5] (Cp* = ,5 -C5Me5) and [Cp*2Mo2O4] were investigated by combined on-line electrochemical (EC) reduction and electrospray-ionization mass spectrometry (ESI-MS) techniques in a trifluoroacetic acid buffered water/methanol solution. The reduction products at the larger negative potentials are identical for both compounds. The studies reveal the existence of a wide range of previously unknown di- and trinuclear MoV, MoIV, MoIII, and mixed-valence complexes that were identified on the basis of their masses and characteristic isotope patterns. The structures of the initial compounds and the product of electroreduction with m/z = 713,729 were supported by in situ MSn experiments that allowed the elucidation of the fragmentation pathway for the collision-induced dissociation. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

DE-loop mutations affect ,2 microglobulin stability, oligomerization, and the low-pH unfolded form

PROTEIN SCIENCE, Issue 7 2010
Carlo Santambrogio
Abstract ,2 microglobulin (,2m) is the light chain of class-I major histocompatibility complex (MHC-I). Its accumulation in the blood of patients affected by kidney failure leads to amyloid deposition around skeletal joints and bones, a severe condition known as Dialysis Related Amyloidosis (DRA). In an effort to dissect the structural determinants of ,2m aggregation, several ,2m mutants have been previously studied. Among these, three single-residue mutations in the loop connecting strands D and E (W60G, W60V, D59P) have been shown to affect ,2m amyloidogenic properties, and are here considered. To investigate the biochemical and biophysical properties of wild-type (w.t.) ,2m and the three mutants, we explored thermal unfolding by Trp fluorescence and circular dichroism (CD). The W60G mutant reveals a pronounced increase in conformational stability. Protein oligomerization and reduction kinetics were investigated by electrospray-ionization mass spectrometry (ESI-MS). All the mutations analyzed here reduce the protein propensity to form soluble oligomers, suggesting a role for the DE-loop in intermolecular interactions. A partially folded intermediate, which may be involved in protein aggregation induced by acids, accumulates for all the tested proteins at pH 2.5 under oxidizing conditions. Moreover, the kinetics of disulfide reduction reveals specific differences among the tested mutants. Thus, ,2m DE-loop mutations display long-range effects, affecting stability and structural properties of the native protein and its low-pH intermediate. The evidence presented here hints to a crucial role played by the DE-loop in determining the overall properties of native and partially folded ,2m. [source]

Electrospray-ionization mass spectrometry as a tool for fast screening of protein structural properties

BIOTECHNOLOGY JOURNAL, Issue 1 2009
Rita Grandori
Abstract Since the early 1990s, electrospray-ionization mass spectrometry (ESI-MS) has encountered growing interest as a complementary tool to established biochemical and biophysical methods for investigating protein structure and conformation. Nowadays, applications of ESI-MS to protein investigation span from the area of analytical biochemistry to that of structural biology. This review focuses on applications of this technique to the analysis of protein conformational properties and molecular interactions, underscoring their possible relevance for molecular biotechnology, although representing a still very young field. An introductive section presents the major issues related to theoretical and technical aspects of ESI-MS under non-denaturing conditions. Examples from our work and from the literature illustrate which kind of information can be obtained concerning key issues in biotechnology such as stability and aggregation of proteins under both near-native and challenging conditions, and interactions with other proteins, ligands and cofactors. [source]

Qualitative and Quantitative HPLC/MS Determination of Proanthocyanidins in Areca Nut (Areca catechu)

CHEMISTRY & BIODIVERSITY, Issue 12 2007
Qingli Wu
Abstract Proanthocyanidins (PACs) in areca nut (Areca catechu L.) were analyzed by high-performance liquid chromatography (HPLC) combined with electrospray-ionization mass spectrometry (ESI-MS) and compared to grape seed extract. Under optimized conditions, the separated PACs were individually analyzed and identified on the basis of their [M+H]+ peaks. The PAC distribution in areca nut was found to be very similar to that in grape seed, but lacking any gallate conjugates. Based on reverse-phase HPLC separation, the PAC monomers (+)-catechin (CA, 1) and (,)-epicatechin (EC; 2) were successfully quantified by ESI-MS in the selected-ion-monitoring (SIM) mode, (,)-epigallocatechin (EGC; 3) being used as internal standard. Detailed quality and validation assays showed that the accuracy and repeatability (n=8) were within 10% for each analyte. [source]