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1.
Chem Commun (Camb) ; 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39109843

RESUMEN

The tertiary and quaternary structures of many proteins are stabilized by strong covalent forces, of which disulfide bonds are the most well known. A new type of intramolecular and intermolecular covalent bond has been recently reported, consisting of the Lys and Cys side-chains linked by an oxygen atom (NOS). These post-translational modifications are widely distributed amongst proteins, and are formed under oxidative conditions. Similar linkages are observed during antibiotic biosynthesis, where hydroxylamine intermediates are tethered to the sulfur of enzyme active site Cys residues. These linkages open the way to understanding protein structure and function, give new insights into enzyme catalysis and natural product biosynthesis, and offer new strategies for drug design.

2.
Biosci Rep ; 44(8)2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39046229

RESUMEN

Human somatic angiotensin-converting enzyme (ACE) is a key zinc metallopeptidase that plays a pivotal role in the renin-angiotensin-aldosterone system (RAAS) by regulating blood pressure and electrolyte balance. Inhibition of ACE is a cornerstone in the management of hypertension, cardiovascular diseases, and renal disorders. Recent advances in structural biology techniques have provided invaluable insights into the molecular mechanisms underlying ACE inhibition, facilitating the design and development of more effective therapeutic agents. This review focuses on the latest advancements in elucidating the structural basis for ACE inhibition. High-resolution crystallographic studies of minimally glycosylated individual domains of ACE have revealed intricate molecular details of the ACE catalytic N- and C-domains, and their detailed interactions with clinically relevant and newly designed domain-specific inhibitors. In addition, the recently elucidated structure of the glycosylated form of full-length ACE by cryo-electron microscopy (cryo-EM) has shed light on the mechanism of ACE dimerization and revealed continuous conformational changes which occur prior to ligand binding. In addition to these experimental techniques, computational approaches have also played a pivotal role in elucidating the structural basis for ACE inhibition. Molecular dynamics simulations and computational docking studies have provided atomic details of inhibitor binding kinetics and energetics, facilitating the rational design of novel ACE inhibitors with improved potency and selectivity. Furthermore, computational analysis of the motions observed by cryo-EM allowed the identification of allosteric binding sites on ACE. This affords new opportunities for the development of next-generation allosteric inhibitors with enhanced pharmacological properties. Overall, the insights highlighted in this review could enable the rational design of novel ACE inhibitors with improved efficacy and safety profiles, ultimately leading to better therapeutic outcomes for patients with hypertension and cardiovascular diseases.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina , Peptidil-Dipeptidasa A , Humanos , Inhibidores de la Enzima Convertidora de Angiotensina/química , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Peptidil-Dipeptidasa A/química , Peptidil-Dipeptidasa A/metabolismo , Simulación de Dinámica Molecular , Relación Estructura-Actividad , Simulación del Acoplamiento Molecular , Sistema Renina-Angiotensina/efectos de los fármacos , Microscopía por Crioelectrón , Unión Proteica , Animales
3.
Hosp Top ; : 1-7, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38841999

RESUMEN

BACKGROUND: Many governments have introduced health insurance schemes for the poor sections of society to save them from catastrophic health expenditure. Private hospitals play a key role in India, as they are in significant number in secondary and tertiary care services. Private hospitals have to fund their infrastructure, staff salaries from the revenue of previous year. In this study, we compared money received by a private medical college hospital bed through government insurance scheme patient and private paying patient. METHODS: Observational study, comparing money reimbursed for top ten procedures treated in private medical college hospitals by Ayushman Bharat (AB) fund and the price offered by a paying patient in similar bed. RESULTS: On average 600 patients received medical care through the AB scheme per month at our tertiary care super-specialty hospital. Highest numbers were seen in specialties like cardiovascular, and cancer treatments and infectious diseases under general medicine specialty. The costs considered were surgeon's cost, medicines, devices, and hospitalization costs. The laparoscopic procedures were incurring a loss of 130%, knee replacements about 50%, coronary bypass grafting thankfully due to controlling of prices by central government is incurring a loss of 10%. The package amount offered accounts to 26-52% only of the costs incurred by the private hospitals. CONCLUSION: The private academic hospitals need 25% to 50% more than current prices offered, across various procedures.

4.
Curr Rheumatol Rev ; 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38803169

RESUMEN

Rheumatoid Arthritis (RA) is a progressive autoimmune condition inflicting serious threats to people's life and health by causing severe pain and joint destruction. It affects not only bones and joints but also causes comorbid conditions and shortens the lifetime. The interactions and synergistic effects of comorbid disease with RA are not yet well studied. Hence, understanding how these conditions will collectively affect the progression and outcome of RA is the current area of research. Identification of RA and comorbidities associated with target genes may uncover diagnosis and treatment methodologies. This review is to provide an overview of the interlinking approach of Rheumatoid Arthritis with its comorbid conditions and its systemic complications using bioinformatic techniques which would be useful to identify the genes and pathways that are in common for both RA and comorbid diseases. It would also emphasize the significance of bioinformatics in comparing the pathological features of RA and comorbid diseases. With the help of bioinformatics, valuable insights into the mechanism underlying Rheumatoid arthritis and comorbid diseases would be better understood.

5.
Phys Chem Chem Phys ; 26(12): 9264-9283, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38446193

RESUMEN

The rising need to produce a decarbonized supply chain of energy critical metals with inherent carbon mineralization motivates advances in accelerating novel chemical pathways in a mechanistically-informed manner. In this study, the mechanisms underlying co-recovery of energy critical metals and carbon mineralization by harnessing organic ligands are uncovered by investigating the influence of chemical and mineral heterogeneity, along with the morphological transformations of minerals during carbon mineralization. Serpentinized peridotite is selected as the feedstock, and disodium EDTA dihydrate (Na2H2EDTA·2H2O) is used as the organic ligand for metal recovery. Nickel extraction efficiency of ∼80% and carbon mineralization efficiency of ∼73% is achieved at a partial pressure of CO2 of 50 bars, reaction temperature of 185 °C, and 10 hours of reaction time in 2 M NaHCO3 and 0.1 M Na2H2EDTA·2H2O. Extensive magnesite formation is evidence of the carbon mineralization of serpentine and olivine. An in-depth investigation of the chemo-morphological evolution of the CO2-fluid-mineral system during carbon mineralization reveals several critical stages. These stages encompass the initial incongruent dissolution of serpentine resulting in a Si-rich amorphous layer acting as a diffusion barrier for Mg2+ ions, subsequent exfoliation of the silica layer to expose unreacted olivine, and the concurrent formation of magnesite. Organic ligands such as Na2H2EDTA·2H2O aid the dissolution and formation of magnesite crystals. The organic ligand exhibits higher stability for Ni-complex ions than the corresponding divalent metal carbonate. The buffered environment also facilitates concurrent mineral dissolution and carbonate formation. These two factors contribute to the efficient co-recovery of nickel with inherent carbon mineralization to produce magnesium carbonate. These studies provide fundamental insights into the mechanisms underlying the co-recovery of energy critical metals with inherent carbon mineralization which unlocks the value of earth abundant silicate resources for the sustainable recovery of energy critical metals and carbon management.

6.
Biomolecules ; 14(3)2024 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-38540719

RESUMEN

α-Methylacyl-CoA racemase in M. tuberculosis (MCR) has an essential role in fatty acid metabolism and cholesterol utilization, contributing to the bacterium's survival and persistence. Understanding the enzymatic activity and structural features of MCR provides insights into its physiological and pathological significance and potential as a therapeutic target. Here, we report high-resolution crystal structures for wild-type MCR in a new crystal form (at 1.65 Å resolution) and for three active-site mutants, H126A, D156A and E241A, at 2.45, 1.64 and 1.85 Å resolutions, respectively. Our analysis of the new wild-type structure revealed a similar dimeric arrangement of MCR molecules to that previously reported and details of the catalytic site. The determination of the structures of these H126A, D156A and E241A mutants, along with their detailed kinetic analysis, has now allowed for a rigorous assessment of their catalytic properties. No significant change outside the enzymatic active site was observed in the three mutants, establishing that the diminution of catalytic activity is mainly attributable to disruption of the catalytic apparatus involving key hydrogen bonding and water-mediated interactions. The wild-type structure, together with detailed mutational and biochemical data, provide a basis for understanding the catalytic properties of this enzyme, which is important for the design of future anti-tuberculosis drug molecules.


Asunto(s)
Mycobacterium tuberculosis , Dominio Catalítico , Mycobacterium tuberculosis/genética , Cinética , Racemasas y Epimerasas/genética
7.
FEBS Lett ; 598(2): 242-251, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37904282

RESUMEN

Human somatic angiotensin-1-converting enzyme (sACE) is composed of a catalytic N-(nACE) and C-domain (cACE) of similar size with different substrate specificities. It is involved in the regulation of blood pressure by converting angiotensin I to the vasoconstrictor angiotensin II and has been a major focus in the development of therapeutics for hypertension. Bioactive peptides from various sources, including milk, have been identified as natural ACE inhibitors. We report the structural basis for the role of two lacototripeptides, Val-Pro-Pro and Ile-Pro-Pro, in domain-specific inhibition of ACE using X-ray crystallography and kinetic analysis. The lactotripeptides have preference for nACE due to altered polar interactions distal to the catalytic zinc ion. Elucidating the mechanism of binding and domain selectivity of these peptides also provides important insights into the functional roles of ACE.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina , Peptidil-Dipeptidasa A , Humanos , Peptidil-Dipeptidasa A/química , Peptidil-Dipeptidasa A/metabolismo , Cinética , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Inhibidores de la Enzima Convertidora de Angiotensina/química , Inhibidores de la Enzima Convertidora de Angiotensina/metabolismo , Angiotensinas
8.
Methods Enzymol ; 690: 1-37, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37858526

RESUMEN

Modern drug discovery is a target-driven approach in which a particular protein such as an enzyme is implicated in the disease process. Commonly, small-molecule drugs are identified using screening, rational design, and structural biology approaches. Drug screening, testing and optimization is typically conducted in vitro, and copious amounts of protein are required. The advent of recombinant DNA technologies has resulted in a rise in proteins purified by affinity techniques, typically by incorporating an "affinity tag" at the N- or C-terminus. Use of these tagged proteins and affinity techniques comes with a host of issues. This chapter describes the production of an untagged enzyme, α-methylacyl-CoA racemase (MCR) from Mycobacterium tuberculosis, using a recombinant E. coli system. Purification of the enzyme on a 100 mg scale using tandem anion-exchange chromatographies (DEAE-sepharose and RESOURCE-Q columns), and size-exclusion chromatographies is described. A modified protocol allowing the purification of cationic proteins is also described, based on tandem cation-exchange chromatographies (using CM-sepharose and RESOURCE-S columns) and size-exclusion chromatographies. The resulting MCR protein is suitable for biochemical and structural biology applications. The described protocols have wide applicability to the purification of other recombinant proteins and enzymes without using affinity chromatography.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Humanos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Cinética , Escherichia coli/genética , Escherichia coli/metabolismo , Sefarosa/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Cromatografía de Afinidad/métodos
9.
Biomolecules ; 13(9)2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37759807

RESUMEN

Plastic pollution has emerged as a significant environmental concern in recent years and has prompted the exploration of innovative biotechnological solutions to mitigate plastic's negative impact. The discovery of enzymes capable of degrading specific types of plastics holds promise as a potential solution. However, challenges with efficiency, industrial scalability, and the diverse range of the plastic waste in question, have hindered their widespread application. Structural biology provides valuable insights into the intricate interactions between enzymes and plastic materials at an atomic level, and a deeper understanding of their underlying mechanisms is essential to harness their potential to address the mounting plastic waste crisis. This review article examines the current biochemical and biophysical methods that may facilitate the development of enzymes capable of degrading polyethylene terephthalate (PET), one of the most extensively used plastics. It also discusses the challenges that must be addressed before substantial advancements can be achieved in using these enzymes as a solution to the plastic pollution problem.

10.
Int J Mol Sci ; 24(16)2023 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-37628902

RESUMEN

Clostridium botulinum neurotoxins (BoNTs) are the most potent toxins known, causing the deadly disease botulism. They function through Zn2+-dependent endopeptidase cleavage of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins, preventing vesicular fusion and subsequent neurotransmitter release from motor neurons. Several serotypes of BoNTs produced by Clostridium botulinum (BoNT/A-/G and/X) have been well-characterised over the years. However, a BoNT-like gene (homologue of BoNT) was recently identified in the non-clostridial species, Enterococcus faecium, which is the leading cause of hospital-acquired multi-drug resistant infections. Here, we report the crystal structure of the catalytic domain of a BoNT homologue from Enterococcus faecium (LC/En) at 2.0 Å resolution. Detailed structural analysis in comparison with the full-length BoNT/En AlphaFold2-predicted structure, LC/A (from BoNT/A), and LC/F (from BoNT/F) revealed putative subsites and exosites (including loops 1-5) involved in recognition of LC/En substrates. LC/En also appears to possess a conserved autoproteolytic cleavage site whose function is yet to be established.


Asunto(s)
Botulismo , Clostridium botulinum , Infección Hospitalaria , Enterococcus faecium , Humanos , Dominio Catalítico , Transporte Biológico
11.
FEBS J ; 2023 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-37622248

RESUMEN

The accumulation of the small 42-residue long peptide amyloid-ß (Aß) has been proposed as a major trigger for the development of Alzheimer's disease (AD). Within the brain, the concentration of Aß peptide is tightly controlled through production and clearance mechanisms. Substantial experimental evidence now shows that reduced levels of Aß clearance are present in individuals living with AD. This accumulation of Aß can lead to the formation of large aggregated amyloid plaques-one of two detectable hallmarks of the disease. Aß-degrading enzymes (ADEs) are major players in the clearance of Aß. Stimulating ADE activity or expression, in order to compensate for the decreased clearance in the AD phenotype, provides a promising therapeutic target. It has been reported in mice that upregulation of ADEs can reduce the levels of Aß peptide and amyloid plaques-in some cases, this led to improved cognitive function. Among several known ADEs, neprilysin (NEP), endothelin-converting enzyme-1 (ECE-1), insulin degrading enzyme (IDE) and angiotensin-1 converting enzyme (ACE) from the zinc metalloprotease family have been identified as important. These ADEs have the capacity to digest soluble Aß which, in turn, cannot form the toxic oligomeric species. While they are known for their amyloid degradation, they exhibit complexity through promiscuous nature and a broad range of substrates that they can degrade. This review highlights current structural and functional understanding of these key ADEs, giving some insight into the molecular interactions that leads to the hydrolysis of peptide substrates, the crucial tasks performed by them and the potential for therapeutic use in the future.

12.
Chem Biodivers ; 20(8): e202201158, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37400965

RESUMEN

An efficient 1,4-dihydropyridine synthesis under mild conditions has been developed. Numerous substrates were tested, with yields of 1,4-dihydropridines ranging from good to excellent and a wide range of functional group tolerance. A549, HT-29, and HepG2 cancer cells were used to investigate the anticancer efficacy of each of the produced compounds. Additionally, in-silico docking studies were conducted to understand the structure-based features of the anticancer mechanism with the cancer medication target of Adenosine A2A receptor as well as the molecular level interactions of the compounds.


Asunto(s)
Antineoplásicos , Dihidropiridinas , Humanos , Células Hep G2 , Dihidropiridinas/farmacología , Dihidropiridinas/química , Células HT29 , Simulación del Acoplamiento Molecular , Antineoplásicos/química , Relación Estructura-Actividad , Estructura Molecular , Ensayos de Selección de Medicamentos Antitumorales
13.
Biomolecules ; 13(7)2023 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-37509168

RESUMEN

A novel protein, PID-5, has been shown to be a requirement for germline immortality and has recently been implicated in RNA-induced epigenetic silencing in the Caenorhabditis elegans embryo. Importantly, it has been shown to contain both an eTudor and aminopeptidase P-related domain. However, the silencing mechanism has not yet been fully characterised. In this study, bioinformatic tools were used to compare pre-existing aminopeptidase P molecular structures to the AlphaFold2-predicted aminopeptidase P-related domain of PID-5 (PID-5 APP-RD). Structural homology, metal composition, inhibitor-bonding interactions, and the potential for dimerisation were critically assessed through computational techniques, including structural superimposition and protein-ligand docking. Results from this research suggest that the metallopeptidase-like domain shares high structural homology with known aminopeptidase P enzymes and possesses the canonical 'pita-bread fold'. However, the absence of conserved metal-coordinating residues indicates that only a single Zn2+ may be bound at the active site. The PID-5 APP-RD may form transient interactions with a known aminopeptidase P inhibitor and may therefore recognise substrates in a comparable way to the known structures. However, loss of key catalytic residues suggests the domain will be inactive. Further evidence suggests that heterodimerisation with C. elegans aminopeptidase P is feasible and therefore PID-5 is predicted to regulate proteolytic cleavage in the silencing pathway. PID-5 may interact with PID-2 to bring aminopeptidase P activity to the Z-granule, where it could influence WAGO-4 activity to ensure the balanced production of 22G-RNA signals for transgenerational silencing. Targeted experiments into APPs implicated in malaria and cancer are required in order to build upon the biological and therapeutic significance of this research.


Asunto(s)
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Dominios Proteicos , Animales , Aminopeptidasas/química , Aminopeptidasas/ultraestructura , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Metales/metabolismo , ARN/metabolismo , Dominios Proteicos/genética , Dominios Proteicos/fisiología
14.
Sci Rep ; 13(1): 8651, 2023 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-37244906

RESUMEN

Selection of plant extracts as bioactive phytochemical source to synthesize nanoparticles is highly demanding due to the biocompatibility, nontoxicity, and cost-effectiveness over other available physical and chemical methods. Here, for the first time, Coffee arabica leaf extracts (CAE) were used to produce highly stable silver nanoparticles (AgNPs) and the corresponding bio reduction, capping and stabilization mechanism mediated by dominant isomer 5-caffeoylquinic acid (5-CQA) is discussed. UV-Vis, FTIR, µRaman spectroscopy, TEM, DLS and Zeta potential analyzer measurements were employed to characterize these green synthesized NPs. The affinity of 5-CQA capped CAE-AgNPs to thiol moiety of amino acid is utilized for the selective as well as sensitive detection of L-cysteine (L-Cys) to a low detection limit of 0.1 nM, as obtained from its µRaman spectra. Hence, the proposed novel, simple, eco-friendly, and economically sustainable method can provide a promising nanoplatform in the field of biosensors compliant with large-scale industrial production of AgNPs without aid of further instrumentation.


Asunto(s)
Nanopartículas del Metal , Nanopartículas del Metal/química , Cisteína , Plata/química , Café , Extractos Vegetales/química , Espectroscopía Infrarroja por Transformada de Fourier , Hojas de la Planta/metabolismo , Antibacterianos
15.
Toxins (Basel) ; 15(2)2023 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-36828407

RESUMEN

Botulinum neurotoxins (BoNTs) cause flaccid neuromuscular paralysis by cleaving one of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex proteins. BoNTs display high affinity and specificity for neuromuscular junctions, making them one of the most potent neurotoxins known to date. There are seven serologically distinct BoNTs (serotypes BoNT/A to BoNT/G) which can be further divided into subtypes (e.g., BoNT/A1, BoNT/A2…) based on small changes in their amino acid sequence. Of these, BoNT/A1 and BoNT/B1 have been utilised to treat various diseases associated with spasticity and hypersecretion. There are potentially many more BoNT variants with differing toxicological profiles that may display other therapeutic benefits. This review is focused on the structural analysis of the cell-binding domain from BoNT/A1 to BoNT/A6 subtypes (HC/A1 to HC/A6), including features such as a ganglioside binding site (GBS), a dynamic loop, a synaptic vesicle glycoprotein 2 (SV2) binding site, a possible Lys-Cys/Cys-Cys bridge, and a hinge motion between the HCN and HCC subdomains. Characterising structural features across subtypes provides a better understanding of how the cell-binding domain functions and may aid the development of novel therapeutics.


Asunto(s)
Toxinas Botulínicas Tipo A , Clostridium botulinum , Toxinas Botulínicas Tipo A/metabolismo , Unión Proteica , Neurotoxinas/metabolismo , Sitios de Unión , Proteínas SNARE/metabolismo , Clostridium/metabolismo , Clostridium botulinum/metabolismo
16.
Int J Mol Sci ; 23(17)2022 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-36077016

RESUMEN

Clostridium botulinum neurotoxin A (BoNT/A) targets the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex, by cleaving synaptosomal-associated protein of 25 kDa size (SNAP-25). Cleavage of SNAP-25 results in flaccid paralysis due to repression of synaptic transmission at the neuromuscular junction. This activity has been exploited to treat a range of diseases associated with hypersecretion of neurotransmitters, with formulations of BoNT/A commercially available as therapeutics. Generally, BoNT activity is facilitated by three essential domains within the molecule, the cell binding domain (HC), the translocation domain (HN), and the catalytic domain (LC). The HC, which consists of an N-terminal (HCN) and a C-terminal (HCC) subdomain, is responsible for BoNT's high target specificity where it forms a dual-receptor complex with synaptic vesicle protein 2 (SV2) and a ganglioside receptor on the surface of motor neurons. In this study, we have determined the crystal structure of botulinum neurotoxin A6 cell binding domain (HC/A6) in complex with GD1a and describe the interactions involved in ganglioside binding. We also present a new crystal form of wild type HC/A6 (crystal form II) where a large 'hinge motion' between the HCN and HCC subdomains is observed. These structures, along with a comparison to the previously determined wild type crystal structure of HC/A6 (crystal form I), reveals the degree of conformational flexibility exhibited by HC/A6.


Asunto(s)
Toxinas Botulínicas Tipo A , Toxinas Botulínicas Tipo A/química , Membrana Celular/metabolismo , Clostridium/metabolismo , Neuronas/metabolismo , Unión Proteica , Vesículas Sinápticas/metabolismo
17.
FEBS J ; 289(21): 6659-6671, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35653492

RESUMEN

Human angiotensin I-converting enzyme (ACE) has two isoforms, somatic ACE (sACE) and testis ACE (tACE). The functions of sACE are widespread, with its involvement in blood pressure regulation most extensively studied. sACE is composed of an N-domain (nACE) and a C-domain (cACE), both catalytically active but have significant structural differences, resulting in different substrate specificities. Even though ACE inhibitors are used clinically, they need much improvement because of serious side effects seen in patients (~ 25-30%) with long-term treatment due to nonselective inhibition of nACE and cACE. Investigation into the distinguishing structural features of each domain is therefore of vital importance for the development of domain-specific inhibitors with minimal side effects. Here, we report kinetic data and high-resolution crystal structures of both nACE (1.75 Å) and cACE (1.85 Å) in complex with fosinoprilat, a clinically used inhibitor. These structures allowed detailed analysis of the molecular features conferring domain selectivity by fosinoprilat. Particularly, altered hydrophobic interactions were observed to be a contributing factor. These experimental data contribute to improved understanding of the structural features that dictate ACE inhibitor domain selectivity, allowing further progress towards designing novel 2nd-generation domain-specific potent ACE inhibitors suitable for clinical administration, with a variety of potential future therapeutic benefits. DATABASE: The atomic coordinates and structure factors for nACE-fosinoprilat and cACE-fosinoprilat structures have been deposited with codes 7Z6Z and 7Z70, respectively, in the RCSB Protein Data Bank, www.pdb.org.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina , Peptidil-Dipeptidasa A , Humanos , Peptidil-Dipeptidasa A/química , Cristalografía por Rayos X , Inhibidores de la Enzima Convertidora de Angiotensina/química , Angiotensinas
18.
Toxins (Basel) ; 14(5)2022 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-35622602

RESUMEN

Botulinum neurotoxins (BoNT) are a group of clostridial toxins that cause the potentially fatal neuroparalytic disease botulism. Although highly toxic, BoNTs are utilized as therapeutics to treat a range of neuromuscular conditions. Several serotypes (BoNT/A-/G, /X) have been identified with vastly differing toxicological profiles. Each serotype can be further sub-categorised into subtypes due to subtle variations in their protein sequence. These minor changes have been attributed to differences in both the duration of action and potency for BoNT/A subtypes. BoNTs are composed of three domains-a cell-binding domain, a translocation domain, and a catalytic domain. In this paper, we present the crystal structures of the botulinum neurotoxin A2 cell binding domain, both alone and in complex with its receptor ganglioside GD1a at 1.63 and 2.10 Å, respectively. The analysis of these structures reveals a potential redox-dependent Lys-O-Cys bridge close to the ganglioside binding site and a hinge motion between the HCN and HCC subdomains. Furthermore, we make a detailed comparison with the previously reported HC/A2:SV2C structure for a comprehensive structural analysis of HC/A2 receptor binding.


Asunto(s)
Toxinas Botulínicas Tipo A , Botulismo , Toxinas Botulínicas Tipo A/metabolismo , Clostridium/metabolismo , Gangliósidos , Humanos , Unión Proteica
19.
J Assoc Physicians India ; 70(4): 11-12, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35443518

RESUMEN

The recent second wave of COVID-19 cases in India has been marked by an unexpected increase in cases of mucormycosis reported in the context of COVID illness. Herein we aim to identify risk factors that may explain the sudden surge of cases and help develop preventive strategies. MATERIAL: We performed a case-control study comparing cases diagnosed with CAM and those who had recovered from COVID-19 without developing mucormycosis (controls). Information on comorbidities, glycemic control, and practices related to COVID-19 treatment was recorded. OBSERVATION: 100 patients of CAM (cases) and 150 patients of COVID-19 without mucormycosis (controls) were included in the study. The spectrum of involvement of CAM cases included rhino-sinus (n=98, 98%), rhino orbital (n=58, 58%), rhino-orbito-cerebral (n=29, 29%). In CAM group symptoms of mucormycosis began a mean of 13.46 days after onset of COVID-19. The mean age of the CAM study group was 51.16 years with 69 males (69%) and 31 females (31.0). The most frequent comorbidities seen in our study population was diabetes (n=113, 45.2%) and hypertension (n=54, 21.6%). Diabetes was significantly more frequent among cases than controls (89% vs 24%, p <0.001). 31% of patients in CAM case group showed a common practise of steam inhalation during covid illness. Most common symptom reported in CAM was related to the eye which included eye pain (58%), lid swelling (54%), eye swelling (47%). Sino-nasal symptoms were nasal discharge (25%), nasal stuffiness (21%), and epistaxis (4%). Other common symptoms were headache (51%) and facial pain (36%). On examination of nasal cavity, crusting and ulceration were present in 83% patients. Eye involvement was present in 60% of cases, of which 27% of cases had vision loss. For definitive diagnosis of CAM, Potassium hydroxide (KOH) mount was positive for aseptate hyphae in 31 patients (31%). Use of systemic steroids for the management of COVID-19, was more frequent in CAM case group than control group (n=70, 70%). The CAM case group showed mean Hba1c of 10.7 ± 2.45, mean Serum Iron levels was 49.01 ± 18.69, mean ferritin was 913.37, mean CRP was 131.56 and mean LDH was 428.70. CONCLUSION: Overzealous use of steroids, uncontrolled sugars and repeated steam inhalation provided a favourable environment for the growth of mucormycosis. Judicious use of steroids and stringent glycemic control are vital to preventing mucormycosis.


Asunto(s)
Tratamiento Farmacológico de COVID-19 , COVID-19 , Diabetes Mellitus , Mucormicosis , COVID-19/epidemiología , Estudios de Casos y Controles , Diabetes Mellitus/epidemiología , Femenino , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Mucormicosis/diagnóstico , Mucormicosis/epidemiología , Mucormicosis/terapia , SARS-CoV-2 , Vapor
20.
J Assoc Physicians India ; 70(4): 11-12, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35443521

RESUMEN

The recent outbreak of COVID 19 is a great threat to public health. Because of limitation of resources, the number of patients that can be monitored and treated in Intensive Care Units is restricted. Hence identifying medical patients at risk of deterioration at the initial stage by means of simple protocols based on physiological parameters is crucial. The qSOFA score was introduced as a rapid bedside clinical score to identify patients with a suspected infection that are at greater risk for a poor outcome. The National Early Warning Score (NEWS) was developed to improve the detection of and response to clinical deterioration in patients with acute illness. There is paucity of literature regarding the use of these scores in patients with COVID 19 infection. This study aims at comparing the scoring systems qSOFA and NEWS in the setting of COVID-19 infection and its correlation with the final outcome of the illness. MATERIAL: It is a retrospective study in which patients presenting with COVID 19 infection(diagnosed by RT-PCR testing of nasopharyngeal and oral swab) between April 2021 to June 2021 were included. Scoring was done using both the scores at admission and the patients were followed up till the outcome. Outcome was defined as 5-day, 10-day and 15-day mortality after presentation. Predictive performance was expressed as discrimination (AUC). Subsequently, sensitivity and specificity were calculated. OBSERVATION: A total of 100 patients were included in the study, of whom 17 died within 5 days and 37 died within 10 days and 30 died within 15 days after presentation. q SOFA had the best performance, compared to NEWS (5 day auc : .668, .621, 10-day auc: .580, .569, 15-day auc: .625, .511) with q SOFA having sensitivity of 90.2% while that of news being 95.1% where as specificity of q SOFA is 40.7% and that of NEWS is 47.5%. CONCLUSION: qSOFA score is more accurate in predicting 5, 10 and 15-day mortality than NEWS score in COVID 19 patients. In resource limited settings, it is an inexpensive and simple tool for early identification of high risk COVID 19 patients.


Asunto(s)
COVID-19 , Puntuación de Alerta Temprana , Sepsis , COVID-19/diagnóstico , Mortalidad Hospitalaria , Humanos , Unidades de Cuidados Intensivos , Puntuaciones en la Disfunción de Órganos , Pronóstico , Estudios Retrospectivos , Sepsis/diagnóstico
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