Search results for "Biochemist"
showing 4 items of 20174 documents
α-Conotoxins EpI and AuIB switch subtype selectivity and activity in native versus recombinant nicotinic acetylcholine receptors
2003
The Xenopus laevis oocyte expression system was used to determine the activities of alpha-conotoxins EpI and the ribbon isomer of AuIB, on defined nicotinic acetylcholine receptors (nAChRs). In contrast to previous findings on intracardiac ganglion neurones, alpha-EpI showed no significant activity on oocyte-expressed alpha3beta4 and alpha3beta2 nAChRs but blocked the alpha7 nAChR with an IC50 value of 30 nM. A similar IC50 value (103 nM) was obtained on the alpha7/5HT3 chimeric receptor stably expressed in mammalian cells. Ribbon AuIB maintained its selectivity on oocyte-expressed alpha3beta4 receptors but unlike in native cells, where it was 10-fold more potent than native alpha-AuIB, had…
Profiling Dopamine-Induced Oxidized Proteoforms of β-synuclein by Top-Down Mass Spectrometry
2021
The formation of multiple proteoforms by post-translational modifications (PTMs) enables a single protein to acquire distinct functional roles in its biological context. Oxidation of methionine residues (Met) is a common PTM, involved in physiological (e.g., signaling) and pathological (e.g., oxidative stress) states. This PTM typically maps at multiple protein sites, generating a heterogeneous population of proteoforms with specific biophysical and biochemical properties. The identification and quantitation of the variety of oxidized proteoforms originated under a given condition is required to assess the exact molecular nature of the species responsible for the process under investigation…
The chemical composition of the aerial parts essential oil of Ferulago nodosa (L.) Boiss. (Apiaceae) growing wild in Crete (Greece)
2023
Ferulago nodosa (L.) Boiss. (Apiaceae) is a species occurring in the Balkan-Tyrrhenian area being present in Crete, Greece, Albania, and probably in Macedonia. Although the western disjointed population of Sicily has been classified as an endemic sub-species, F. nodosa subsp. geniculata (Guss.) Troia & Raimondo, its official acceptance is quite controversial. In order to verify the existence of two different sub-species, we investigated the chemical composition of the essential oil of F. nodosa, collected in Crete (Greece), not previously reported, and we compared it with the previously oil compositions reported in literature. Main constituents of the Cretan accessions of F. nodosa were…
Characterization and antimicrobial activity of the volatile components of the flowers of Magydaris tomentosa (Desf.) DC. collected in Sicily and Alge…
2014
The essential oils of the flowers of Magydaris tomentosa (Desf.) DC. (Apiaceae) collected in Sicily (MSi) and Algeria (MAl), respectively, were obtained by hydrodistillation, and their compositions were analysed. The analyses allowed the identification and quantification of 23 components in MSi and 60 compounds in MAl, respectively, showing a very different profile in the composition of the two populations. The main components of MSi were cembrene (28.2%), α-springene (17.5%) and β-springene (14.8%), also present in MAl but in lesser amount (0.4%, 1.8% and 0.9%, respectively), whereas the principal constituents of MAl were (E)-nerolidol (35.4%), α-costol (13.3%) and β-costol (6.8%). Both MS…