scholarly journals Tear Lipocalin and Lipocalin-Interacting Membrane Receptor

2021 ◽  
Vol 12 ◽  
Author(s):  
Ben J. Glasgow
Keyword(s):  
Solution Structure ◽  
Drug Carrier ◽  
Cysteine Proteases ◽  
Lipid Binding ◽  
Membrane Receptor ◽  
Surface Epithelium ◽  
Chronic Obstructive ◽  
Putative Receptor ◽  
Wide Range ◽  
Tear Lipocalin

Tear lipocalin is a primate protein that was recognized as a lipocalin from the homology of the primary sequence. The protein is most concentrated in tears and produced by lacrimal glands. Tear lipocalin is also produced in the tongue, pituitary, prostate, and the tracheobronchial tree. Tear lipocalin has been assigned a multitude of functions. The functions of tear lipocalin are inexorably linked to structural characteristics that are often shared by the lipocalin family. These characteristics result in the binding and or transport of a wide range of small hydrophobic molecules. The cavity of tear lipocalin is formed by eight strands (A–H) that are arranged in a β-barrel and are joined by loops between the β-strands. Recently, studies of the solution structure of tear lipocalin have unveiled new structural features such as cation-π interactions, which are extant throughout the lipocalin family. Lipocalin has many unique features that affect ligand specificity. These include a capacious and a flexible cavity with mobile and short overhanging loops. Specific features that confer promiscuity for ligand binding in tear lipocalin will be analyzed. The functions of tear lipocalin include the following: antimicrobial activities, scavenger of toxic and tear disruptive compounds, endonuclease activity, and inhibition of cysteine proteases. In addition, tear lipocalin binds and may modulate lipids in the tears. Such actions support roles as an acceptor for phospholipid transfer protein, heteropolymer formation to alter viscosity, and tear surface interactions. The promiscuous lipid-binding properties of tear lipocalin have created opportunities for its use as a drug carrier. Mutant analogs have been created to bind other molecules such as vascular endothelial growth factor for medicinal use. Tear lipocalin has been touted as a useful biomarker for several diseases including breast cancer, chronic obstructive pulmonary disease, diabetic retinopathy, and keratoconus. The functional possibilities of tear lipocalin dramatically expanded when a putative receptor, lipocalin-interacting membrane receptor was identified. However, opposing studies claim that lipocalin-interacting membrane receptor is not specific for lipocalin. A recent study even suggests a different function for the membrane protein. This controversy will be reviewed in light of gene expression data, which suggest that tear lipocalin has a different tissue distribution than the putative receptor. But the data show lipocalin-interacting membrane receptor is expressed on ocular surface epithelium and that a receptor function here would be rational.

scholarly journals Chemical Synthesis and NMR Solution Structure of Conotoxin GXIA from Conus geographus

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 60
Author(s):  
David A. Armstrong ◽  
Ai-Hua Jin ◽  
Nayara Braga Emidio ◽  
Richard J. Lewis ◽  
Paul F. Alewood ◽  
...  
Keyword(s):  
Solution Structure ◽  
3D Structure ◽  
Voltage Sensor ◽  
Solution Nmr ◽  
Striking Similarity ◽  
Amino Acid Peptide ◽  
Wide Range ◽  
Cone Snails ◽  
Drug Leads ◽  
Β Sheet

Conotoxins are disulfide-rich peptides found in the venom of cone snails. Due to their exquisite potency and high selectivity for a wide range of voltage and ligand gated ion channels they are attractive drug leads in neuropharmacology. Recently, cone snails were found to have the capability to rapidly switch between venom types with different proteome profiles in response to predatory or defensive stimuli. A novel conotoxin, GXIA (original name G117), belonging to the I3-subfamily was identified as the major component of the predatory venom of piscivorous Conus geographus. Using 2D solution NMR spectroscopy techniques, we resolved the 3D structure for GXIA, the first structure reported for the I3-subfamily and framework XI family. The 32 amino acid peptide is comprised of eight cysteine residues with the resultant disulfide connectivity forming an ICK+1 motif. With a triple stranded β-sheet, the GXIA backbone shows striking similarity to several tarantula toxins targeting the voltage sensor of voltage gated potassium and sodium channels. Supported by an amphipathic surface, the structural evidence suggests that GXIA is able to embed in the membrane and bind to the voltage sensor domain of a putative ion channel target.

scholarly journals The innate immune function of airway epithelial cells in inflammatory lung disease

2015 ◽  
Vol 45 (4) ◽  
pp. 1150-1162 ◽  
Author(s):  
Pieter S. Hiemstra ◽  
Paul B. McCray ◽  
Robert Bals
Keyword(s):  
Immune Responses ◽  
Airway Epithelium ◽  
Cell Function ◽  
Developmental Regulation ◽  
Airway Epithelial Cells ◽  
Chronic Obstructive ◽  
Airway Epithelial ◽  
Tissue Remodelling ◽  
Wide Range ◽  
Differentiation Pathways

The airway epithelium is now considered to be central to the orchestration of pulmonary inflammatory and immune responses, and is also key to tissue remodelling. It acts as the first barrier in the defence against a wide range of inhaled challenges, and is critically involved in the regulation of both innate and adaptive immune responses to these challenges. Recent progress in our understanding of the developmental regulation of this tissue, the differentiation pathways, recognition of pathogens and antimicrobial responses is now exploited to help understand how epithelial cell function and dysfunction contributes to the pathogenesis of a variety of inflammatory lung diseases. Herein, advances in our knowledge of the biology of airway epithelium, as well as its role and (dys)function in asthma, chronic obstructive pulmonary fibrosis and cystic fibrosis will be discussed.

scholarly journals PECULIARITIES OF APOPTOTIC MARKER EXPRESSION IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND ARTERIAL HYPERTENSION

2018 ◽  
Vol 18 (4) ◽  
pp. 65-71
Author(s):  
O.S. Tyaglaya
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Essential Hypertension ◽  
Arterial Hypertension ◽  
Pulmonary Disease ◽  
Cysteine Proteases ◽  
Chronic Obstructive ◽  
Significant Elevation ◽  
Caspase 9 ◽  
Obstructive Pulmonary Disease ◽  
Caspase 7

It is known that both chronic obstructive pulmonary disease and arterial hypertension are multifactorial diseases, and develop as a result of a complex interaction of genetic and environmental factors. The purpose of this work was to study the metabolism of caspase-7 and caspase-9 in patients with chronic obstructive pulmonary disease (COPD) in combination with arterial hypertension (AH). Materials and methods. We examined 23 patients with a diagnosis of essential hypertension stage II and COPD stage II without a clinically significant concomitant pathology. The plasma level of caspase-7 and caspase-9 was determined using the appropriate ELISA test systems (manufacturer – Bender Medsystems, Austria) at the Medical and Laboratory Training Centre of Zaporizhzhia State Medical University in accordance with the instructions attached to the kit. The analysis of the dynamics of the studied cysteine ​​proteases indicates a statistically significant elevation of these apoptosis markers in the conditions of hypertension and COPD. The value of caspase-7 in the cohort of patients with COPD + AH significantly exceeded similar figures for the groups of patients with a single pathology presented by AH or COPD, and averaged 0.41 ± 0.09 ng / ml. A statistically significant elevation of the caspase-9 level in patients with COPD + AH up to 2.16 ± 0.29 ng / ml compared with other groups also indicates a more significant induction of apoptotic processes in comorbid pathology than in isolated AH or COPD. Conclusion. The obtained results require further clarification of the nature of the relationship between changes in the metabolism of cysteine ​​proteases and the primacy of pathogenetic processes in the mechanisms of risk formation for complications and progression of ventilation disorders in patients with COPD and comorbid essential hypertension.

scholarly journals Dilute Solution Structure of Bottlebrush Polymers

2019 ◽  
Author(s):  
Sarit Dutta ◽  
Matthew A. Wade ◽  
Dylan J. Walsh ◽  
Damien Guironnet ◽  
Simon A. Rogers ◽  
...  
Keyword(s):  
Brownian Dynamics ◽  
Solution Structure ◽  
Coarse Grained ◽  
Poly Lactic Acid ◽  
Linear Polymers ◽  
Molecular Architecture ◽  
Wide Range ◽  
Conformational Properties ◽  
Atomistic Structure ◽  
Insight Into

<div>Bottlebrush polymers are a class of macromolecules that has recently found use</div><div>in a wide variety of materials, ranging from lubricating brushes and</div><div>nanostructured coatings to elastomeric gels that exhibit structural color. These</div><div>polymers are characterized by dense branches extending from a central backbone,</div><div>and thus have properties distinct from linear polymers. It remains a challenge</div><div>to specifically understand conformational properties of these molecules, due to</div><div>the wide range of architectural parameters that can be present in a system, and</div><div>thus there is a need to accurately characterize and model these molecules. In</div><div>this paper, we use a combination of viscometry, light scattering, and computer</div><div>simulations to gain insight into the conformational properties of dilute</div><div>bottlebrush polymers. We focus on a series of model bottlebrushes consisting of</div><div>a poly(norbornene) (PNB) backbone with poly(lactic acid) (PLA) side chains. We</div><div>demonstrate that intrinsic viscosity and hydrodynamic radius are experimental</div><div>observations \emph{sensitive} to molecular architecture, exhibiting distinct</div><div>differences with different choices of branch and backbone lengths. Informed by</div><div>the atomistic structure of this PNB-PLA system, we rationalize a coarse-grained</div><div>simulation model that we evaluate using a combination of Brownian Dynamics and</div><div>Monte Carlo simulations. We show that this exhibits quantitative matching to</div><div>experimental results, enabling us to characterize the overall shape of the</div><div>bottlebrush via a number of metrics that can be extended to more general</div><div>bottlebrush architectures.</div>

scholarly journals The solution structure of pGolemi, a high affinity Mena EVH1 binding miniature protein, suggests explanations for paralog-specific binding to Ena/VASP homology (EVH) 1 domains

2009 ◽  
Vol 390 (5/6) ◽  
Author(s):  
Nina M. Link ◽  
Cornelia Hunke ◽  
Jonathan W. Mueller ◽  
Jutta Eichler ◽  
Peter Bayer
Keyword(s):  
Solution Structure ◽  
Specific Binding ◽  
Transmembrane Protein ◽  
Structural Data ◽  
Adaptor Proteins ◽  
Axonal Guidance ◽  
High Affinity ◽  
Binding Domains ◽  
Wide Range ◽  
Pancreatic Peptide

Abstract Ena/VASP homology 1 (EVH1) domains are polyproline binding domains that are present in a wide range of adaptor proteins, among them Ena/VASP proteins involved in actin remodeling and axonal guidance. The interaction of ActA, a transmembrane protein from the food-borne pathogen Listeria monocytogenes, with EVH1 domains has been shown to be crucial for recruitment of the host's actin skeleton and, as a consequence, for the infectivity of this bacterium. We present the structure of a synthetic high-affinity Mena EVH1 ligand, pGolemi, capable of paralog-specific binding, solved by NMR spectroscopy. This peptide shares the common pancreatic peptide fold with its scaffold, avian pancreatic peptide, but shows pivotal differences in the amino-terminus. The interplay of spatial fixation and flexibility appears to be the reason for its high affinity towards Mena EVH1. Combined with earlier investigations, our structural data shed light on the specificity determinants of pGolemi and the importance of additional binding epitopes around the residues Thr74 and Phe32 on EVH1 domains regulating paralog specificity. Our results are expected to facilitate the design of other high-affinity, paralog-specific EVH1 domain ligands, and serve as a fundament for the investigation of the molecular mode of action of EVH1 domains.

scholarly journals Blastocystis ratti Contains Cysteine Proteases That Mediate Interleukin-8 Response from Human Intestinal Epithelial Cells in an NF-κB-Dependent Manner

2007 ◽  
Vol 7 (3) ◽  
pp. 435-443 ◽  
Author(s):  
Manoj K. Puthia ◽  
Jia Lu ◽  
Kevin S. W. Tan
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Intestinal Inflammation ◽  
Experimental Studies ◽  
Cysteine Proteases ◽  
Interleukin 8 ◽  
Dependent Manner ◽  
Public Health Importance ◽  
Wide Range ◽  
First Time

ABSTRACT Blastocystis is a ubiquitous enteric protozoan found in the intestinal tracts of humans and a wide range of animals. Evidence accumulated over the last decade suggests association of Blastocystis with gastrointestinal disorders involving diarrhea, abdominal pain, constipation, nausea, and fatigue. Clinical and experimental studies have associated Blastocystis with intestinal inflammation, and it has been shown that Blastocystis has potential to modulate the host immune response. Blastocystis is also reported to be an opportunistic pathogen in immunosuppressed patients, especially those suffering from AIDS. However, nothing is known about the parasitic virulence factors and early events following host-parasite interactions. In the present study, we investigated the molecular mechanism by which Blastocystis activates interleukin-8 (IL-8) gene expression in human colonic epithelial T84 cells. We demonstrate for the first time that cysteine proteases of Blastocystis ratti WR1, a zoonotic isolate, can activate IL-8 gene expression in human colonic epithelial cells. Furthermore, we show that NF-κB activation is involved in the production of IL-8. In addition, our findings show that treatment with the antiprotozoal drug metronidazole can avert IL-8 production induced by B. ratti WR1. We also show for the first time that the central vacuole of Blastocystis may function as a reservoir for cysteine proteases. Our findings will contribute to an understanding of the pathobiology of a poorly studied parasite whose public health importance is increasingly recognized.

scholarly journals Patterns of use, survival and prognostic factors in patients receiving home mechanical ventilation in Western Australia: A single centre historical cohort study

2018 ◽  
Vol 15 (4) ◽  
pp. 356-364 ◽  
Author(s):  
Geak Poh Tan ◽  
Nigel McArdle ◽  
Satvinder Singh Dhaliwal ◽  
Jane Douglas ◽  
Clare Siobhan Rea ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Pulmonary Disease ◽  
Western Australia ◽  
Sleep Apnoea ◽  
Forced Expiratory Volume ◽  
Chronic Obstructive ◽  
Home Mechanical Ventilation ◽  
Historical Cohort ◽  
Patterns Of Use ◽  
Wide Range

Home mechanical ventilation (HMV) is used in a wide range of disorders associated with chronic hypoventilation. We describe the patterns of use, survival and predictors of death in Western Australia. We identified 240 consecutive patients (60% male; mean age 58 years and body mass index 31 kg m−2) referred for HMV between 2005 and 2010. The patients were grouped into four categories: motor neurone disorders (MND; 39%), pulmonary disease (PULM; 25%, mainly chronic obstructive pulmonary disease), non-MND neuromuscular and chest wall disorders (NMCW; 21%) and the obesity hypoventilation syndrome (OHS; 15%). On average, the patients had moderate ventilatory impairment (forced vital capacity: 51%predicted), sleep apnoea (apnoea-hypopnea index: 25 events h−1), sleep-related hypoventilation (transcutaneous carbon dioxide rise of 20 mmHg) and daytime hypercarbia (PCO2: 54 mmHg). Median durations of survival from HMV initiation were 1.0, 4.2, 9.9 and >11.5 years for MND, PULM, NMCW and OHS, respectively. Independent predictors of death varied between primary indications for HMV; the predictors included (a) age in all groups except for MND (hazard ratios (HRs) 1.03–1.10); (b) cardiovascular disease (HR: 2.35, 95% confidence interval (CI): 1.08–5.10) in MND; (c) obesity (HR: 0.28, 95% CI: 0.13–0.62) and oxygen therapy (HR: 0.33, 95% CI: 0.14–0.79) in PULM; and (d) forced expiratory volume in 1 s (%predicted; HR: 0.93, 95% CI: 0.88–1.00) in OHS.

Chronic respiratory failure

2020 ◽  
pp. 4282-4291
Author(s):  
Michael I. Polkey ◽  
P.M.A. Calverley
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Respiratory Failure ◽  
Neuromuscular Diseases ◽  
Interstitial Lung Diseases ◽  
Alveolar Ventilation ◽  
Chronic Respiratory Failure ◽  
Clinical State ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Wide Range

Chronic respiratory failure describes a clinical state when the arterial Po2 breathing air is less than 8.0 kPa, which may or may not be associated with hypercapnia (defined as Pco2 more than 6.0 kPa (45 mm Hg)). Four processes cause arterial hypoxaemia due to inefficient pulmonary gas exchange—ventilation–perfusion (V/Q) mismatch, hypoventilation, diffusion limitation, and true shunt, with the most important of these being V/Q mismatching. The arterial CO2 is increased by inadequate alveolar ventilation and/or V/Q abnormality. A wide range of disorders can cause chronic respiratory failure, with the commonest being chronic obstructive pulmonary disease, interstitial lung diseases, chest wall and neuromuscular diseases, and morbid obesity.

scholarly journals The binding of cholesterol and bile salts to recombinant rat liver fatty acid-binding protein

1996 ◽  
Vol 320 (3) ◽  
pp. 729-733 ◽  
Author(s):  
Alfred E. A. THUMSER ◽  
David C. WILTON
Keyword(s):  
Fatty Acid ◽  
Bile Salts ◽  
Fatty Acid Binding Protein ◽  
Binding Protein ◽  
Physiological Role ◽  
Lipid Binding ◽  
Liver Fatty Acid ◽  
Fatty Acid Binding ◽  
Acid Binding Protein ◽  
Wide Range

The physiological role of liver fatty acid-binding protein (L-FABP) has yet to be clarified. An important feature of this member of the family of intracellular lipid-binding proteins is the wide range of compounds that have been identified as potential physiological ligands. By using recombinant L-FABP, the binding of cholesterol, bile salts and their derivatives has been investigated under conditions that allow a direct comparison of the binding affinities of these ligands for fatty acids. The results demonstrate an inability of L-FABP to bind cholesterol, although the anionic derivative, cholesteryl sulphate, will bind under similar assay conditions. Of the bile salts examined, lithocholate and taurolithocholate sulphate showed the greatest binding to L-FABP. It is proposed that an important function of L-FABP is to bind certain physiological amphipathic anions, thus preventing the ‘free’ concentrations of these compounds from exceeding their critical micelle concentration, which could result in cell damage.

scholarly journals Comparison between electronic and paper versions of patient-reported outcome measures in subjects with chronic obstructive pulmonary disease: an observational study with a cross-over administration

BMJ Open ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. e032767
Author(s):  
Koichi Nishimura ◽  
Masaaki Kusunose ◽  
Ryo Sanda ◽  
Yousuke Tsuji ◽  
Yoshinori Hasegawa ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Intraclass Correlation ◽  
Patient Reported Outcome ◽  
Elderly Subjects ◽  
Chronic Obstructive ◽  
Care Hospital ◽  
Obstructive Pulmonary Disease ◽  
Wide Range ◽  
Patient Reported

ObjectivesA wide range of electronic devices can be used for data collection of patient-reported outcome (PRO) measures in subjects with chronic obstructive pulmonary disease (COPD). Although comparisons between electronic and paper-based PRO measures have been undertaken in asthmatics, it is currently uncertain whether electronic questionnaires work equally as well as paper versions in elderly subjects with COPD. The aim of this study was to compare the responses to paper and electronic versions of the Evaluating Respiratory Symptoms in COPD (E-RS) and the COPD Assessment Test (CAT).DesignA randomised cross-over design was used to compare the responses to paper and electronic versions of the two tools. The interval between the two administrations was 1 week.SettingElectronic versions were self-administered under supervision using a tablet computer at our outpatient clinic (secondary care hospital in Japan) while paper questionnaires completed at home were requested to be returned by mail. It was intended that half of the patients completed the electronic versions of both questionnaires first, followed by the paper versions while the other half completed the paper versions first.ParticipantsEighty-one subjects with stable COPD were included.ResultsThe E-RS total scores (possible range 0–40) were 6.8±7.4 and 5.0±6.6 in the paper-based and electronic versions, respectively, and the CAT scores (possible range 0–40) were 10.0±7.4 and 8.6±7.8. In both questionnaires, higher scores indicate worse status. The relationship between electronic and paper versions showed significant reliability for both the E-RS total score and CAT score (intraclass correlation coefficient=0.82 and 0.89, respectively; both p<0.001). However, both the E-RS total and CAT scores were significantly higher in the paper versions (p<0.05).ConclusionsIn both cases, the two versions of the same questionnaire cannot be used interchangeably even though they have both been validated.

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