Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 21
Filter
Add more filters










Publication year range
1.
Drug Discov Today ; 29(7): 104020, 2024 May 11.
Article in English | MEDLINE | ID: mdl-38740363

ABSTRACT

Necroptosis has emerged as one of the crucial pathological processes involved in the regulation of cell death and inflammation in chronic obstructive pulmonary disease (COPD). Airway epithelial necroptosis is closely linked to COPD pathogenesis. Necroptotic lung cells can release damage-associated molecular patterns (DAMPs) that can initiate a robust inflammatory response. However, the underlying mechanism of necroptosis in COPD is still not clearly understood. Therefore, we aimed to explore the roles and mechanisms of receptor-interacting serine/threonine-protein kinase 1 (RIPK1)-mediated necroptosis in the regulation of inflammatory responses in COPD to provide insights into RIPK1-inhibitor drug discovery efforts and their therapeutic benefits in COPD.

2.
Neurotherapeutics ; : e00362, 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38664194

ABSTRACT

Genomic screened homeobox 1 (Gsx1 or Gsh1) is a neurogenic transcription factor required for the generation of excitatory and inhibitory interneurons during spinal cord development. In the adult, lentivirus (LV) mediated Gsx1 expression promotes neural regeneration and functional locomotor recovery in a mouse model of lateral hemisection spinal cord injury (SCI). The LV delivery method is clinically unsafe due to insertional mutations to the host DNA. In addition, the most common clinical case of SCI is contusion/compression. In this study, we identify that adeno-associated virus serotype 6 (AAV6) preferentially infects neural stem/progenitor cells (NSPCs) in the injured spinal cord. Using a rat model of contusion SCI, we demonstrate that AAV6 mediated Gsx1 expression promotes neurogenesis, increases the number of neuroblasts/immature neurons, restores excitatory/inhibitory neuron balance and serotonergic neuronal activity through the lesion core, and promotes locomotor functional recovery. Our findings support that AAV6 preferentially targets NSPCs for gene delivery and confirmed Gsx1 efficacy in clinically relevant rat model of contusion SCI.

3.
Toxicol Mech Methods ; 34(1): 57-71, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37680063

ABSTRACT

BACKGROUND: Iron is one of the essential metals that functions as a cofactor in various biological cascades in the brain. However, excessive iron accumulation in the brain may lead to neurodegeneration and may show toxic effects. Quercetin, a pigment flavonoid compound, has been proven to be a potent antioxidant and anti-inflammatory that can inhibit lipid peroxidation during metal-induced neurotoxicity. Although iron-induced neuroinflammation and neurodegeneration have been reported in many studies, but the proof for its exact mechanisms needs to be explored. PURPOSE: The key target of the study was to explore the neuroprotective effect of quercetin after oral exposure of iron in rats and explore its underlying molecular mechanisms. RESULTS: The outcomes of the study have shown that oral exposure to ferrous sulfate may modulate behavioral paradigms such as locomotor activity, neuromuscular coordination, and increased anxiety level. The pro-inflammatory cytokines (TNF-α, IL-1ß and IL-6), apoptotic protein (caspase 3), beta-amyloid and phosphorylated tau were found to be increased on iron exposure. Also, the expressions of ferritin heavy and light chain, BACE-1 and GFAP expressions were altered. These behavioral, structural, and biochemical alterations in the brain were significantly and dose-dependently reversed by treatment with quercetin. CONCLUSION: The current study provides a fundamental understanding of molecular signaling pathways, and structural proteins implicated in iron-induced neurotoxicity along with the ameliorative effects of quercetin.


Subject(s)
Neuroprotective Agents , Quercetin , Rats , Animals , Quercetin/pharmacology , Iron/toxicity , Iron/metabolism , Antioxidants/metabolism , Brain , Signal Transduction , Neuroprotective Agents/pharmacology , Neuroprotective Agents/therapeutic use
4.
Biomed Mater ; 18(6)2023 10 24.
Article in English | MEDLINE | ID: mdl-37827172

ABSTRACT

Recently, photodynamic therapy (PDT) has received a lot of attention for its potential use in cancer treatment. It enables the therapy of a multifocal disease with the least amount of tissue damage. The most widely used prodrug is 5-aminolevulinic acid, which undergoes heme pathway conversion to protoporphyrin IX, which acts as a photosensitizer (PS). Additionally, hematoporphyrin, bacteriochlorin, and phthalocyanine are also studied for their therapeutic potential in cancer. Unfortunately, not every patient who receives PDT experiences a full recovery. Resistance to different anticancer treatments is commonly observed. A few of the resistance mechanisms by which cancer cells escape therapeutics are genetic factors, drug-drug interactions, impaired DNA repair pathways, mutations related to inhibition of apoptosis, epigenetic pathways, etc. Recently, much research has been conducted to develop a new generation of PS based on nanomaterials that could be used to overcome cancer cells' multidrug resistance (MDR). Various metal-based, polymeric, lipidic nanoparticles (NPs), dendrimers, etc, have been utilized in the PDT application against cancer. This article discusses the detailed mechanism by which cancer cells evolve towards MDR as well as recent advances in PDT-based NPs for use against multidrug-resistant cancers.


Subject(s)
Neoplasms , Photochemotherapy , Humans , Drug Resistance, Multiple , Drug Resistance, Neoplasm , Neoplasms/drug therapy , Photosensitizing Agents/therapeutic use
5.
Expert Opin Biol Ther ; 23(7): 603-618, 2023.
Article in English | MEDLINE | ID: mdl-37334564

ABSTRACT

INTRODUCTION: Recombinant monoclonal antibodies (mAbs) are highly selective and effective biologicals with proven utility as therapeutics. mAbs have demonstrated substantial promise in the treatment of several central nervous system diseases. AREAS COVERED: Databases including PubMed and Clinicaltrials.gov were used to identify clinical studies of mAbs involving patients with neurological disorders. This manuscript reviews the current status and recent advances in the development and engineering of therapeutic blood-brain barrier (BBB)-crossing mAbs and their potential in treatment of central nervous system diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), brain tumors, and neuromyelitis optica spectrum disorder (NMSOD). In addition, the clinical implications of recently developed monoclonal antibodies are also discussed, along with the strategies to enhance their BBB permeability. The adverse events associated with the administration of monoclonal antibodies are also presented in the manuscript. EXPERT OPINION: There is growing evidence that supports the therapeutic utility of monoclonal antibodies in central nervous system and neurodegenerative diseases. Several studies have offered evidence of clinical efficacy in AD through use of anti-amyloid beta antibodies and anti-tau passive immunotherapy-based strategies. Additionally, ongoing research trials have produced promising findings for the treatment of brain tumors and NMSOD.


Subject(s)
Alzheimer Disease , Brain Neoplasms , Humans , Antibodies, Monoclonal/adverse effects , Blood-Brain Barrier , Central Nervous System , Brain Neoplasms/drug therapy , Alzheimer Disease/drug therapy
6.
J Org Chem ; 88(11): 7477-7482, 2023 Jun 02.
Article in English | MEDLINE | ID: mdl-37163612

ABSTRACT

An efficient, mild, and novel route is developed to synthesize sulfonylurea via the nickel-catalyzed tandem coupling of sulfonyl azide, isocyanide, and water in aqueous media. The sulfonyl azide is expected to act as a nitrene precursor, which upon reaction with isocyanide generates carbodiimide. Herein, water acts as a nucleophile and reacts with carbodiimide to deliver the product. The protocol uses an inexpensive nickel catalyst, environmentally friendly water (as the nucleophile), and room temperature and provides products in moderate to good yields.

7.
Curr Alzheimer Res ; 20(1): 38-47, 2023.
Article in English | MEDLINE | ID: mdl-37138423

ABSTRACT

BACKGROUND: Microglial overactivation promotes the production of various second messengers and inflammatory markers in brain tissue, resulting in neuroinflammation and neurodegeneration, which may lead to cognitive decline. The cyclic nucleotides are one of the important second messengers involved in the regulation of neurogenesis, synaptic plasticity, and cognition. The levels of these cyclic nucleotides are maintained by phosphodiesterase enzyme isoforms, particularly PDE4B, in the brain. An imbalance between PDE4B levels and cyclic nucleotides may lead to aggravating neuroinflammation. METHODS: Lipopolysaccharides (LPS) were administered intraperitoneally on alternate days for 7 days at a dose of 500 µg/kg in mice, which triggered systemic inflammation. This may lead to the activation of glial cells and may activate oxidative stress and neuroinflammatory markers in brain tissue. Furthermore, oral administration of roflumilast (0.1, 0.2, and 0.4 mg/kg) in this model ameliorated oxidative stress markers, neuroinflammation and improved neurobehavioral parameters in these animals. RESULTS: The detrimental effect of LPS increased oxidative stress, AChE enzyme levels, and decreased catalase levels in brain tissues, along with memory impairment in animals. Moreover, it also enhanced the activity and expression of the PDE4B enzyme, resulting in a decline in cyclic nucleotide levels. Furthermore, treatment with roflumilast improved the cognitive decline, decreased AChE enzyme level, and increased the catalase enzyme level. Roflumilast also reduced the PDE4B expression in a dose-dependent manner, which LPS up-regulated. CONCLUSION: Roflumilast has shown an anti-neuroinflammatory effect and reversed the cognitive decline in LPS-induced mice model.


Subject(s)
Lipopolysaccharides , Neuroinflammatory Diseases , Mice , Animals , Lipopolysaccharides/toxicity , Catalase/metabolism , Catalase/pharmacology , Disease Models, Animal , Inflammation/chemically induced , Inflammation/drug therapy , Brain/metabolism , Nucleotides, Cyclic/metabolism , Nucleotides, Cyclic/pharmacology
8.
Talanta ; 258: 124418, 2023 Jun 01.
Article in English | MEDLINE | ID: mdl-36931059

ABSTRACT

Ammonia detection is needed in several sectors including environmental monitoring, automobile industry, and in medical diagnosis. Conducting polymers, such as polyaniline (PANI), have been utilized to develop NH3 sensors operating at room temperature. However, the performance of these sensors in terms of sensitivity and selectivity need improvement. Functionalization of conducting PANI with metal nanocomposites have shown improved sensor performance. In this work, we report a highly sensitive copper-based nanocomposite for NH3 detection. The novelty lies in utilization of copper-ethylenediamine (Cu-en) nanocomposite functionalized over PANI for gas sensing. Resistance of the 20 wt% Cu-en with PANI increased 3.8 times upon exposure to 100 ppm of NH3. The nanocomposite sensor detected NH3 concentrations as low as 2 ppm. Further, the sensing mechanism was studied by in-situ IV characteristics and impedance spectroscopy during NH3 exposure. NH3 showed ionic interaction with PANI, and Cu2+. The strong affinity of Cu2+ for the lone pair of NH3 enhanced the sensor response from 0.78 to 3.8 for 100 ppm of NH3 at 20 °C. The sensor response was completely recovered after heating at 75 °C, which indicates reusability of the sensor. The sensor showed selectivity for NH3 over ethanol and H2S. The response was reasonably stable after bending the flexible sensor for 1000 times at a radius of 5 mm.

9.
Biomater Adv ; 149: 213395, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36990023

ABSTRACT

In the age of fathoming biomedical predicaments, ardently emerged the field of materiobiology to effectively counter the archetypal and outdated therapies. Correspondingly, the subpar activity of the over-the-counter wound dressing pharmaceuticals have been dominated with the implementation of biocompatible, water-retaining exotic hydrogels to facilitate accelerated diabetic wound healing. Considering a strategy to develop a pragmatic biomimetic scaffold having the ability of dynamic wound healing with diminutive inflammation, we investigated the creation of graphene quantum dot (GQD)-polyacrylic acid (PAA) hybrid hydrogel. We observe appropriate percentage of GQD incorporation in PAA to demonstrate lower pro-inflammatory cytokines, interleukin (IL-6), and tumour necrosis factor (TNF-α) along with higher anti-inflammatory (IL-10) expressions in contrast to natural and standard controls. Likewise, histological examinations corresponding to the in-vitro and in-vivo toxicological analysis of GQD-PAA manifested to be a non-toxic, biocompatible saviour of diabetic wounds. This hybrid hydrogel reports the quickest diabetic wound healing of 13 days. Additionally, the hybrid hydrogel also demonstrates salient antibacterial activity against E. coli. We explore a multifaceted mechanistic approach attributed by the hybrid framework as an avant-garde solution in materiobiology and diabetic wound healing nexus. We believe the GQD-hybrid hydrogel reveals an advancement that could portray a new horizon against diabetic wounds.


Subject(s)
Diabetes Mellitus , Graphite , Quantum Dots , Humans , Hydrogels , Graphite/pharmacology , Quantum Dots/therapeutic use , Escherichia coli , Biomimetics , Wound Healing
10.
Neurochem Res ; 48(6): 1663-1690, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36763312

ABSTRACT

The inflammatory and immunological responses play a significant role after stroke. The innate immune activation stimulated by microglia during stroke results in the migration of macrophages and lymphocytes into the brain and are responsible for tissue damage. The immune response and inflammation following stroke have no defined targets, and the intricacies of the immunological and inflammatory processes are only partially understood. Innate immune cells enter the brain and meninges during the acute phase, which can cause ischemia damage. Activation of systemic immunity is caused by danger signals sent into the bloodstream by injured brain cells, which is followed by a significant immunodepression that encourages life-threatening infections. Neuropsychiatric sequelae, a major source of post-stroke morbidity, may be induced by an adaptive immune response that is initiated by antigen presentation during the chronic period and is directed against the brain. Thus, the current review discusses the role of immune response and inflammation in stroke pathogenesis, their role in the progression of injury during the stroke, and the emerging targets for the modulation of the mechanism of immune response and inflammation that may have possible therapeutic benefits against stroke.


Subject(s)
Brain Ischemia , Stroke , Humans , Stroke/drug therapy , Inflammation/drug therapy , Brain/pathology , Macrophages/pathology , Brain Ischemia/drug therapy , Immunity
11.
Bioinspir Biomim ; 18(1)2022 12 19.
Article in English | MEDLINE | ID: mdl-36533860

ABSTRACT

Flagella and cilia are slender structures that serve important functionalities in the microscopic world through their locomotion induced by fluid and structure interaction. With recent developments in microscopy, fabrication, biology, and modeling capability, robots inspired by the locomotion of these organelles in low Reynolds number flow have been manufactured and tested on the micro-and macro-scale, ranging from medicalin vivomicrobots, microfluidics to macro prototypes. We present a collection of modeling theories, control principles, and fabrication methods for flagellated and ciliary robots.


Subject(s)
Cilia , Flagella , Locomotion
12.
Bioconjug Chem ; 33(12): 2370-2380, 2022 12 21.
Article in English | MEDLINE | ID: mdl-36383773

ABSTRACT

The complex social ecosystem regulates the spectrum of human behavior. However, it becomes relatively easier to understand if we disintegrate the contributing factors, such as locality and interacting partners. Interestingly, it draws remarkable similarity with the behavior of a residue placed in a social setup of functional groups in a protein. Can it inspire principles for creating a unique environment for the precision engineering of proteins? We demonstrate that localization-regulated interacting partner(s) could render precise and traceless single-site modification of structurally diverse native proteins. The method targets a combination of high-frequency Lys residues through an array of reversible and irreversible reactions. However, excellent simultaneous control over chemoselectivity, site selectivity, and modularity ensures that the user-friendly protocol renders acyl group installation, including post-translational modifications (PTMs), on a single Lys. Besides, it offers a chemically orthogonal handle for the installation of probes. Also, a purification protocol integration delivers analytically pure single-site tagged protein bioconjugates. The precise labeling of a surface Lys residue ensures that the structure and enzymatic activities remain conserved post-bioconjugation. For example, the precise modification of insulin does not affect its uptake and downstream signaling pathway. Further, the method enables the synthesis of homogeneous antibody-fluorophore and antibody-drug conjugates (AFC and ADC; K183 and K249 labeling). The trastuzumab-rhodamine B conjugate displays excellent serum stability along with antigen-specific cellular imaging. Further, the trastuzumab-emtansine conjugate offers highly specific antiproliferative activity toward HER-2 positive SKBR-3 breast cancer cells. This work validates that disintegrate theory can create a comprehensive platform to enrich the chemical toolbox to meet the technological demands at the chemistry, biology, and medicine interface.


Subject(s)
Ecosystem , Lysine , Humans , Lysine/chemistry , Proteins/chemistry , Trastuzumab/chemistry , Catalysis
13.
Front Pharmacol ; 13: 986668, 2022.
Article in English | MEDLINE | ID: mdl-36339626

ABSTRACT

Parkinson's disease is the second most common progressive neurodegenerative disease diagnosed mainly based on clinical symptoms caused by loss of nigrostriatal dopaminergic neurons. Although currently available pharmacological therapies provide symptomatic relief, however, the disease continues to progress eventually leading to severe motor and cognitive decline and reduced quality of life. The hallmark pathology of Parkinson's disease includes intraneuronal inclusions known as Lewy bodies and Lewy neurites, including fibrillar α-synuclein aggregates. These aggregates can progressively spread across synaptically connected brain regions leading to emergence of disease symptoms with time. The α-synuclein level is considered important in its fibrillization and aggregation. Nucleic acid therapeutics have recently been shown to be effective in treating various neurological diseases, raising the possibility of developing innovative molecular therapies for Parkinson's disease. In this review, we have described the advancements in genetic dysregulations in Parkinson's disease along with the disease-modifying strategies involved in genetic regulation with particular focus on downregulation of α-synuclein gene using various novel technologies, notably antisense oligonucleotides, microRNA, short interfering RNA, short hairpin RNAs, DNA aptamers, and gene therapy of vector-assisted delivery system-based therapeutics. In addition, the current status of preclinical and clinical development for nucleic acid-based therapies for Parkinson's disease have also been discussed along with their limitations and opportunities.

14.
Sci Rep ; 12(1): 19263, 2022 Nov 10.
Article in English | MEDLINE | ID: mdl-36357484

ABSTRACT

The effect of radiation-reaction force on the dynamics of a charged particle in an intense focused light wave is investigated using the physically appealing Hartemann-Luhmann equation of motion. It is found that, irrespective of the choice of initial conditions, radiation reaction force causes the charged particle to cross the focal region, provided the particle is driven into regions where the radiation reaction force dominates over the Lorentz force, thus enhancing the forward energy gained by the particle from the intense light wave. This result is in sharp contrast to the well known result, derived in the absence of radiation reaction forces, where for certain initial conditions the particle reflects from the high intensity region of the focused light wave, thereby losing forward energy. From the perspective of energy gain, our studies clearly show that the parameter space for forward energy gain which is reduced by ponderomotive effects is compensated by radiation reaction effects. These results, which are of relevance to the present day direct laser acceleration schemes of charged particle, also agrees with that obtained using the well known Landau-Lifshitz equation of motion.

15.
Methods Enzymol ; 675: 383-396, 2022.
Article in English | MEDLINE | ID: mdl-36220278

ABSTRACT

The proteins are critical building blocks of living systems and serve as a tool for their investigation and intervention. Their precision engineering enables its tuning and expands the functional landscape. Among various proteinogenic amino acids, high-frequency lysine offers a promising bioconjugation target. However, it is also among the most challenging candidates for homogeneous single-site modification. The linchpin-directed modification (LDM) addresses this concern by offering chemoselective, site-selective, and modular protein bioconjugation. The protocol outlines a general method for single-site modification of a native protein. At first, the selected LDM reagent constructs a stable bioconjugate through acylation of the Lys side chain. Subsequently, its chemically orthogonal handle creates an opportunity to install desired probes directly. Alternatively, the same group enables bioconjugate enrichment through ordered immobilization. The subsequent release, coupled with probe installation, renders analytically pure single-site tagged protein bioconjugate. The analysis of these constructs involves intact MS of protein bioconjugate, peptide mapping, and MS-MS for the site of modification and homogeneity.


Subject(s)
Lysine , Proteins , Amino Acids/chemistry , Lysine/chemistry , Proteins/chemistry
16.
Front Plant Sci ; 13: 978205, 2022.
Article in English | MEDLINE | ID: mdl-36035686

ABSTRACT

Within-species variation is a key component of biodiversity and linking it to climatic gradients may significantly improve our understanding of ecological processes. High variability can be expected in plant traits, but it is unclear to which extent it varies across populations under different climatic conditions. Here, we investigated seed trait variability and its environmental dependency across a latitudinal gradient of two widely distributed dune-engineering species (Thinopyrum junceum and Calamagrostis arenaria). Seed germination responses against temperature and seed mass were compared within and among six populations exposed to a gradient of temperature and precipitation regimes (Spiekeroog, DE; Bordeaux, FR; Valencia, ES; Cagliari, IT, Rome, IT; Venice, IT). Seed germination showed opposite trends in response to temperature experienced during emergence in both species: with some expectation, in populations exposed to severe winters, seed germination was warm-cued, whereas in populations from warm sites with dry summer, seed germination was cold-cued. In C. arenaria, variability in seed germination responses disappeared once the seed coat was incised. Seed mass from sites with low precipitation was smaller than that from sites with higher precipitation and was better explained by rainfall continentality than by aridity in summer. Within-population variability in seed germination accounted for 5 to 54%, while for seed mass it was lower than 40%. Seed trait variability can be considerable both within- and among-populations even at broad spatial scale. The variability may be hardly predictable since it only partially correlated with the analyzed climatic variables, and with expectation based on the climatic features of the seed site of origin. Considering seed traits variability in the analysis of ecological processes at both within- and among-population levels may help elucidate unclear patterns of species dynamics, thereby contributing to plan adequate measures to counteract biodiversity loss.

17.
Inorg Chem ; 61(29): 11484-11496, 2022 Jul 25.
Article in English | MEDLINE | ID: mdl-35801575

ABSTRACT

Five new mononuclear lanthanide complexes, [LnL2][Et3NH]·THF/H2O (Ln = Nd, Tb, Dy) (H2LCl = 2-bis(2-hydroxy-3,5-dichloro benzyl)aminomethyl]pyridine), Ln = Nd (1), Tb (2), and Dy (3), and (H2LBr = 2-bis(2-hydroxy-3,5-dibromo benzyl)aminomethyl]pyridine), Ln = Nd (4, H2O) and Tb (5), were synthesized and structurally characterized by single-crystal X-ray diffraction analyses. Being isostructural in all the five cases, the metal center is octa-coordinated with a triangular dodecahedron (D2d symmetry) geometry, and it is independent of the halogen substitution (Cl/Br). This close similarity is due to the composite interplay of hydrogen/halogen bond interactions that control the overall crystal packing, yet notable differences in association patterns among the individual ones arise from the subtle stereo-electronic requirement of individual molecules in the three-dimensional (3D) architecture. Hirshfeld surface and density functional theory (DFT) calculations clearly vouch for the importance of the hydrogen bond and halogen bond interactions observed in the structure. Detailed magnetic measurements using direct-current and alternating-current susceptibility measurements show slow magnetic relaxation in 3, a characteristic feature of the single-molecule magnets (SMMs), which is not shown by 1 and 2. Steady-state and time-resolved photoluminescence of Tb(III) complexes shows a strong ligand-to-metal energy transfer that can be modulated by changing the substitution on phenolic ligands. The results from these analyses indicate that it may be advantageous to consider the subtle role of hydrogen bond (HB)/halogen bond (XB) intermolecular interactions judiciously for the design of SMMs and luminescent materials based on halogen-substituted ligands.

18.
Chem Asian J ; 17(17): e202200515, 2022 Sep 01.
Article in English | MEDLINE | ID: mdl-35833469

ABSTRACT

In this study, we report the polymorphism of six coordinated Sn(IV)- tetrabromophenyl porphyrins axially armed with fluorine-substituted phenolate ligands (structural formula [Sn(TBrPP)2+ (A- )2 ], where A is the axial ligand=3,5-difluoro phenol, compound 1). One form stabilizes in triclinic system (namely, 1α), and the other stabilizes in monoclinic system (namely, 1ß). The two 1α and 1ß polymorphs display distinct photophysical and morphological properties in the solid state. X-ray diffraction study reveals that these polymorphs 1α and 1ß significantly differ in their supramolecular architecture, different axial phenolate conformations, and noncovalent interactions, which are responsible for their distinct solid-state properties. The crystal packing of these polymorphs dominates by intermolecular C-H⋅⋅⋅F, C-H⋅⋅⋅π and C-Br⋅⋅⋅F interhalogen interactions. Furthermore, the solid-state emission spectra of 1α showed red-shifted emission bands with respect to 1ß, in addition the redox behavior of 1α is slightly different in comparison to 1ß. Complementary theoretical studies with Hirshfeld surface analysis show the definite role of Br⋅⋅⋅F interhalogen interactions in the overall stability. Mapping the electrostatic potential isosurfaces with the aid of density functional theory in compound 1 clearly shows the presence of σ-hole, a requisite feature to show halogen interactions in the crystalline state. In addition, lattice energy and single point energy calculation shows that 1α was found to be energetically more favorable and thermodynamically more stable compare to 1ß.


Subject(s)
Porphyrins , Ligands , Models, Molecular , Molecular Conformation , Porphyrins/chemistry , Quantum Theory
19.
Biophys J ; 120(17): 3807-3819, 2021 09 07.
Article in English | MEDLINE | ID: mdl-34265263

ABSTRACT

Hemoglobin-mediated transport of dioxygen (O2) critically depends on the stability of the reduced (Fe2+) form of the heme cofactors. Some protein mutations stabilize the oxidized (Fe3+) state (methemoglobin, Hb M), causing methemoglobinemia, and can be lethal above 30%. The majority of the analyses of factors influencing Hb oxidation are retrospective and give insights only for inner-sphere mutations of heme (His58, His87). Herein, we report the first all-atom molecular dynamics simulations on both redox states and calculations of the Marcus electron transfer (ET) parameters for the α chain Hb oxidation and reduction rates for Hb M. The Hb wild-type (WT) and most of the studied α chain variants maintain globin structure except the Hb M Iwate (H87Y). The mutants forming Hb M tend to have lower redox potentials and thus stabilize the oxidized (Fe3+) state (in particular, the Hb Miyagi variant with K61E mutation). Solvent reorganization (λsolv 73-96%) makes major contributions to reorganization free energy, whereas protein reorganization (λprot) accounts for 27-30% except for the Miyagi and J-Buda variants (λprot ∼4%). Analysis of heme-solvent H-bonding interactions among variants provide insights into the role of Lys61 residue in stabilizing the Fe2+ state. Semiclassical Marcus ET theory-based calculations predict experimental kET for the Cyt b5-Hb complex and provide insights into relative reduction rates for Hb M in Hb variants. Thus, our methodology provides a rationale for the effect of mutations on the structure, stability, and Hb oxidation reduction rates and has potential for identification of mutations that result in methemoglobinemia.


Subject(s)
Electrons , Methemoglobin , Heme , Hemoglobins/genetics , Hemoglobins/metabolism , Methemoglobin/metabolism , Oxidation-Reduction , Retrospective Studies
20.
Sci Rep ; 10(1): 9321, 2020 06 09.
Article in English | MEDLINE | ID: mdl-32518370

ABSTRACT

Bovine milk is vital for infant nutrition and is a major component of the human diet. Bovine mastitis is a common inflammatory disease of mammary gland in cattle. It alters the immune profile of the animal and lowers the quality and yield of milk causing huge economic losses to dairy industry. The incidence of sub-clinical mastitis (SCM) is higher (25-65% worldwide) than clinical mastitis (CM) (>5%), and frequently progresses to clinical stage due to lack of sensitive and specific detection method. We used quantitative proteomics to identify changes in milk during sub-clinical mastitis, which may be potential biomarkers for developing rapid, non-invasive, sensitive detection methods. We performed comparative proteome analysis of the bovine milk, collected from the Indian hybrid cow Karan Fries. The differential proteome in the milk of Indian crossbred cows during sub-acute and clinical intramammary gland infection has not been investigated to date. Using high-resolution mass spectrometry-based quantitative proteomics of the bovine whey proteins, we identified a total of 1459 and 1358 proteins in biological replicates, out of which 220 and 157 proteins were differentially expressed between normal and infected samples. A total of 82 proteins were up-regulated and 27 proteins were down-regulated, having fold changes of ≥2 and ≤0.8 respectively. Among these proteins, overexpression of CHI3L1, LBP, GSN, GCLC, C4 and PIGR proteins was positively correlated with the events that elicit host defence system, triggering production of cytokines and inflammatory molecules. The appearance of these potential biomarkers in milk may be used to segregate affected cattle from the normal herd and may support mitigation measures for prevention of SCM and CM.


Subject(s)
Biomarkers/analysis , Mastitis, Bovine/metabolism , Milk Proteins/analysis , Proteomics/methods , Tandem Mass Spectrometry/methods , Animals , Biomarkers/metabolism , Cattle , Female , Mastitis, Bovine/diagnosis , Milk/chemistry , Milk/cytology , Milk Proteins/metabolism , Protein Interaction Maps , Whey Proteins/analysis
SELECTION OF CITATIONS
SEARCH DETAIL
...