Search results for "HILIC"
showing 10 items of 745 documents
Influence of hydrophobic matching on association of model transmembrane fragments containing a minimised glycophorin A dimerisation motif
2005
AbstractThe principles that govern the folding and packing of membrane proteins are still not completely understood. In the present work, we have revisited the glycophorin A (GpA) dimerisation motif that mediates transmembrane (TM) helix association, one of the best-suited models of membrane protein oligomerisation. By using artificial polyleucine TM segments we have demonstrated in this study that a pattern of only five amino acids (GVxxGVxxT) promotes specific dimerisation. Further, we have used this minimised GpA motif to assess the influence of hydrophobic matching on the TM helix packing process in detergent micelles and found that this factor modulates helix–helix association and/or d…
Transmembrane but not soluble helices fold inside the ribosome tunnel
2018
Integral membrane proteins are assembled into the ER membrane via a continuous ribosome-translocon channel. The hydrophobicity and thickness of the core of the membrane bilayer leads to the expectation that transmembrane (TM) segments minimize the cost of harbouring polar polypeptide backbones by adopting a regular pattern of hydrogen bonds to form α-helices before integration. Co-translational folding of nascent chains into an α-helical conformation in the ribosomal tunnel has been demonstrated previously, but the features governing this folding are not well understood. In particular, little is known about what features influence the propensity to acquire α-helical structure in the ribosom…
Direct evidence that FK506 inhibition of FcεRI-mediated exocytosis from RBL mast cells involves calcineurin
1998
eRI-mediated exocytosis of preformed mediators from mast cells and basophils (e.g. histamine, serotonin, beta-hexosaminidase) is sensitive to the immunosuppressants cyclosporin A and FK506 (IC 50 200 and 4 n M , respectively) but not rapamycin. The mechanism of inhibition does not appear to involve tyrosine phosphorylation, hydrolysis of inositol phosphates or calcium flux. Here we report experiments using a molecular approach to assess the role of calcineurin, a serine/threonine phosphatase thought to be the primary pharmacological target of these drugs. Calcineurin’s activity requires association of its catalytic (A) subunit with an intrinsic regulatory (B) subunit. We hypothesized that c…
Atomic mean square displacements in proteins by Molecular Dynamics: a case for analysis of variance
2004
Information on protein internal motions is usually obtained through the analysis of atomic mean-square displacements, which are a measure of variability of the atomic positions distribution functions. We report a statistical approach to analyze molecular dynamics data on these displacements that is based on probability distribution functions. Using a technique inspired by the analysis of variance, we compute unbiased, reliable mean-square displacements of the atoms and analyze them statistically. We applied this procedure to characterize protein thermostability by comparing the results for a thermophilic enzyme and a mesophilic homolog. In agreement with previous experimental observations, …
Regioselective C–H amination of free base porphyrins via electrogenerated pyridinium-porphyrins and stabilization of easily oxidized amino-porphyrins…
2020
Four free base aminoporphyrins were synthesized in two steps via regioselective anodic nucleophilic substitution with pyridine followed by ring opening of the electrogenerated pyridinium with piperidine. The X-ray crystallographic structure of the unstable 2-aminotetraphenylporphyrin was solved. Protonation of this latter compound leads to the stable diiminium porphyrin salt.
Predicting Responders to Reslizumab after 16 Weeks of Treatment Using an Algorithm Derived from Clinical Studies of Patients with Severe Eosinophilic…
2018
Reslizumab is a humanized anti-IL-5 monoclonal antibody used as add-on maintenance treatment for patients with uncontrolled eosinophilic asthma.To predict response and nonresponse to intravenous reslizumab at 52 weeks with an algorithm we developed based on clinical indicators from pivotal clinical trials.Patients aged 18 years and older who met Global Initiative for Asthma 4 or 5 criteria and received intravenous reslizumab (n = 321) in two trials ( www.clinicaltrials.gov identifiers, NCT01287039 and NCT01285323) were selected as the data source. A mathematical model was constructed that was based on change from baseline to 16 weeks in Asthma Control Questionnaire and Asthma Quality of Lif…
Age is associated with asthma phenotypes
2017
Background and objective The relationship between age and asthma phenotypes is important as population is ageing, asthma is becoming common in older ages and recently developed treatments for asthma are guided by phenotypes. The aim of this study is to evaluate whether age is associated with specific asthma phenotypes. Methods This is a cross-sectional study. We included subjects with asthma of varied degrees of severity. Subjects underwent spirometry, skin prick test to aeroallergens, answered the Asthma Control Questionnaire and had blood samples collected. We performed binary logistic regression analysis to evaluate whether age is associated with asthma phenotypes. Results We enrolled 86…
Therapeutic effects of benralizumab assessed in patients with severe eosinophilic asthma: Real-life evaluation correlated with allergic and non-aller…
2021
Corrado Pelaia,1 Claudia Crimi,2 Alida Benfante,3 Maria Filomena Caiaffa,4 Cecilia Calabrese,5 Giovanna Elisiana Carpagnano,6 Domenico Ciotta Jnr,7 Maria D’Amato,8 Luigi Macchia,9 Santi Nolasco,2 Girolamo Pelaia,1 Simona Pellegrino,7 Nicola Scichilone,3 Giulia Scioscia,10 Giuseppe Spadaro,11 Giuseppe Valenti,12 Alessandro Vatrella,7 Nunzio Crimi2 1Department of Health Sciences, University “Magna Graecia” of Catanzaro, Catanzaro, Italy; 2Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy; 3Department of Biomedicine and Internal and Specialistic Medicine, University of Palermo, Palermo, Italy; 4Allergology and Clinical Immunol…
Severe eosinophilic asthma: a roadmap to consensus
2017
Asthma is widely accepted as a complex heterogeneous condition with diverse pathophysiological mechanisms, clinical presentations, comorbidities, physiological characteristics, pathology and outcomes that is typically best managed by a multidisciplinary team [1–4]. Severe asthma is recognised as a major unmet need with a high personal and social impact, as well as a high burden on healthcare resources [4]. As a consequence of advances in the development of precision medicines for patients with severe asthma, the need to identify asthma subtypes by phenotype based on clinical, functional or inflammatory parameters is becoming a mandatory part of management [4–6]. Severe eosinophilic asthma (…
Stratification of eosinophilic asthma patients treated with reslizumab and GINA Step 4 or 5 therapy
2017
Reslizumab, an anti-interleukin-5 monoclonal antibody, significantly reduces exacerbation frequency and improves lung function, asthma control and quality of life in adults with severe eosinophilic asthma, as demonstrated in Phase III studies. This secondary analysis assessed reslizumab's efficacy in patients receiving baseline treatment per Global Initiative for Asthma (GINA) Step 4 and Step 5 guidelines. Pooled data from duplicate, Phase III, reslizumab versus placebo studies in patients with severe eosinophilic asthma (blood eosinophils ≥400 cells·µL−1) were stratified by baseline therapy. Efficacy assessments were exacerbation rates and changes from baseline forced expiratory volume in …