Target-based virtual screening, computational multiscoring docking and molecular dynamics simulation of small molecules as promising drug candidate affecting kinesin-like protein KIFC1.

The kinesin family member C1 (KIFC1) is an essential protein that facilitates the bipolar division of neoplastic cells. Inhibiting KIFC1 by small molecules is a lucrative strategy to impede bipolar mitosis leading to the apoptosis of cancerous cells. The research aims to envisage small-molecule inhibitors targeting KIFC1. The Mcule database, a comprehensive online digital platform containing more than five million chemical compounds, was used for structure-based virtual screening (SBVS). Druglikeness filtration sifted 2,293,282 chemical hits that further narrowed down to 49 molecules after toxicity profiling. Finally, 39 compounds that comply with the BOILED-Egg permeation predictive model of the ADME rules were carried forward for multiscoring docking using the AutoDock Vina inbuilt to Mcule drug discovery platform, DockThor and SwissDock tools. The mean of ΔG terms produced by docking tools was computed to find consensus top ligand hits. AZ82 exhibited stronger binding (Consensus ΔG: -7.99 kcal mol-1 ) with KIFC1 among reference inhibitors, for example, CW069 (-7.57 kcal mol-1 ) and SR31527 (-7.01 kcal mol-1 ). Ten ligand hits namely, Mcule-4895338547 (Consensus ΔG: -8.69 kcal mol-1 ), Mcule-7035674888 (-8.42 kcal mol-1 ), Mcule-5531166845 (-8.53 kcal mol-1 ), Mcule-3248415882 (-8.55 kcal mol-1 ), Mcule-291881733 (-8.41 kcal mol-1 ), Mcule-5918624394 (-8.44), Mcule-3470115427 (-8.47), Mcule-3686193135 (-8.18 kcal mol-1 ), Mcule-3955355291 (8.09 kcal mol-1 ) and Mcule-9534899193 (-8.01 kcal mol-1 ) depicted strong binding interactions with KIFC1 in comparison to potential reference inhibitor AZ82. The top four ligands and AZ82 were considered for molecular dynamics simulation of 50 ns duration. Toxicity profiling, physicochemical properties, lipophilicity, solubility, pharmacokinetics, druglikeness, medicinal chemistry attributes, average potential energy, RMSD, RMSF, SASA, ΔGsolv and Rg analyses forecast the ligand mcule-4895338547 as a promising inhibitor of KIFC1.

Ellagic acid protects type II collagen induced arthritis in rat via diminution of IKB phosphorylation and suppression IKB-NF-kB complex activation: in vivo and in silico study.

OBJECTIVE: The present study was designed to explore the potential anti-inflammatory and anti-arthritic effects of ellagic acid (EA) in collagen-induced arthritis (CIA). METHODS: CIA rats were treated with MTX (0.25 mg/kg body wt.) and EA (50 mg/kg b.wt.) for a period of 20 days. The effects of treatment in the rats were assessed biochemically by analyzing inflammatory mediators (NF-kB, iNOS, TNF-α, IL-1ß, IL-6 and IL-10) and oxidative stress related parameters (MPO, NO, LPO, catalase, SOD, GSH). In addition, we also assessed the expression of some inflammatory mediators TNF-α, CD8 + though immunohistochemistry in the joint tissue. RESULTS: In the present study, we found expression and synthesis of transcription factor NF-kB was prominent in CIA rats. In addition, main pro-inflammatory cytokines such as TNF-α, IL-1ß, IL-6, and the anti-inflammatory IL-10, was also stand out. Further, reactive oxygen/nitrogen species was also elevated in CIA rats. Treatment with EA ameliorates all the above mentioned inflammatory and oxidative stress related parameters to near normal. Further, we also confirmed the expression of TNF-α, CD8+ T cells through immunohistochemistry was mitigates in joint tissue of EA treated rats. We find EA significantly inhibited the developmental phase of arthritis. CONCLUSION: These results suggest that EA act as potent anti-arthritic and anti-inflammatory agent that could be used as a tool for the development of new drug for the treatment of arthritis.

Enzyme targeting strategies for prevention and treatment of cancer: Implications for cancer therapy.

Extensive growth of cancer in humans is a major cause of death. Numerous studies are being conducted to improve the early diagnosis, prevention, and treatment of cancer. Recent technological advancements in medical science and research indicate molecular target therapy holds much promise in cancer treatment. In the past, therapeutic and diagnostic targeting of non-glycolytic and glycolytic enzymes in cancer have been successful, and discoveries of biomarker enzymes in cancer hold promise for therapeutic treatments. In this review, we discuss the roles of several cancer-associated enzymes that could potentially act as therapeutic targets, and place special focus on non-glycolytic and glycolytic enzymes. This review indicates that the targeting of metabolic signaling offers a promising means of developing novel anti-cancer therapies.

Fibromodulin and regulation of the intricate balance between myoblast differentiation to myocytes or adipocyte-like cells.

Interactions between myoblasts and the surrounding microenvironment led us to explore the role of fibromodulin (FMOD), an extracellular matrix protein, in the maintenance of myoblast stemness and function. Microarray analysis of FMODkd myoblasts and in silico studies were used to identify the top most differentially expressed genes in FMODkd, and helped establish that FMOD-based regulations of integral membrane protein 2a and clusterin are essential components of the myogenic program. Studies in knockout, obese, and diabetic mouse models helped characterize the operation of a novel FMOD-based regulatory circuit that controls myoblast switching from a myogenic to a lipid accumulation fate. FMOD regulation of myoblasts is an essential part of the myogenic program, and it offers opportunities for the development of therapeutics for the treatment of different muscle diseases.-Lee, E. J., Jan, A. T., Baig, M. H., Ahmad, K., Malik, A., Rabbani, G., Kim, T., Lee, I.-K., Lee, Y. H., Park, S.-Y., Choi, I. Fibromodulin and regulation of the intricate balance between myoblast differentiation to myocytes or adipocyte-like cells.

Multi-Spectroscopic Characterization of Human Serum Albumin Binding with Cyclobenzaprine Hydrochloride: Insights from Biophysical and In Silico Approaches.

Cyclobenzaprine hydrochloride (CBH) is a well-known muscle relaxant that is widely used to relieve muscle spasms and other pain associated with acute musculoskeletal conditions. In this study, we elucidated the binding characteristics of this muscle relaxant to human serum albumin (HSA). From a pharmaceutical and biochemical viewpoint, insight into the structure, functions, dynamics, and features of HSA-CBH complex holds great importance. The binding of CBH with this major circulatory transport protein was studied using a combination of biophysical approaches such as UV-VIS absorption, fluorescence quenching, and circular dichroism (CD) spectroscopy. Various in silico techniques, molecular docking and molecular dynamics, were also used to gain deeper insight into the binding. A reduction in the fluorescence intensities of HSA-CBH complex with a constant increase in temperature, revealed the static mode of protein fluorescence quenching upon CBH addition, which confirmed the formation of the HSA-CBH ground state complex. The alteration in the UV-VIS and far-UV CD spectrum indicated changes in both secondary and tertiary structures of HSA upon binding of CBH, further proving CBH binding to HSA. The analysis of thermodynamic parameters ∆H° and ∆S° showed that binding of CBH to HSA was dominated by intermolecular hydrophobic forces. The results of the molecular docking and molecular dynamics simulation studies also confirmed the stability of the complex and supported the experimental results.

Insight of the Interaction between 2,4-thiazolidinedione and Human Serum Albumin: A Spectroscopic, Thermodynamic and Molecular Docking Study.

Thiazolidinedione derivatives (TZDs) have attracted attention because of their pharmacological effects. For example, certain TZDs have been reported to ameliorate type II diabetes by binding and activating PPARs (peroxisome proliferator-activated receptors). Nonetheless, no information is available on the interaction between the heterocyclic 2, 4-thiazolidinedione (2,4-TZD) moiety and serum albumin, which could affect the pharmacokinetics and pharmacodynamics of TZDs. In this study, we investigated the binding of 2,4-TZD to human serum albumin (HSA). Intrinsic fluorescence spectroscopy revealed a 1:1 binding stoichiometry between 2,4-TZD and HSA with a binding constant (Kb) of 1.69 ± 0.15 × 103 M-1 at 298 K. Isothermal titration calorimetry studies showed that 2,4-TZD/HSA binding was an exothermic and spontaneous reaction. Molecular docking analysis revealed that 2,4-TZD binds to HSA subdomain IB and that the complex formed is stabilized by van der Waal's interactions and hydrogen bonds. Molecular dynamics simulation confirmed the stability of the HSA-TZD complex. Further, circular dichroism and 3D fluorescence studies showed that the global conformation of HSA was slightly altered by 2,4-TZD binding, enhancing its stability. The results obtained herein further help in understanding the pharmacokinetic properties of thiazolidinedione.

Binding of Tolperisone Hydrochloride with Human Serum Albumin: Effects on the Conformation, Thermodynamics, and Activity of HSA.

Tolperisone hydrochloride (TH) has muscle relaxant activity and has been widely used for several years in clinical practice to treat pathologically high skeletal muscle tone (spasticity) and related pains. The current study was designed to explore the binding efficacy of TH with human serum albumin (HSA) using multispectrscopic, calorimetric approach, FRET, esterase-like activity, and a molecular docking method. A reduction in fluorescence emission at 340 nm of HSA was attributed to fluorescence quenching by TH via a static quenching type. Binding constants ( Kb) were evaluated at different temperatures, and obtained Kb values were ∼104 M-1, which demonstrated moderately strong affinity of TH for HSA. A calculated negative Δ G° value indicated spontaneous binding of TH to HSA. Far-UV CD spectroscopy revealed that the α-helix content was increased after TH binding. The binding distance between donor and acceptor was calculated to be 2.11 nm based on Förster's resonance energy transfer theory. ITC results revealed TH interacted with HSA via hydrophobic interactions and hydrogen bonding. The thermal stability of HSA was studied using DSC, and results showed that in the presence of TH the structure of HSA was significantly more thermostable. The esterase-like activity of HSA showed fixed Vmax and increased Km suggesting that TH binds with HSA in a competitive manner. Furthermore, molecular docking results revealed TH binds in the cavity of HSA, that is, subdomain IIA (Sudlow site I), and that it hydrogen bonds with K199 and H242 of HSA. Binding studies of drugs with HSA are potentially useful for elucidating chemico-biological interactions that can be utilized in the drug design, pharmaceutical, pharmacology, and biochemistry fields. This extensive study provides additional insight of ligand binding and structural changes induced in HSA relevant to the biological activity of HSA in vivo.

Biophysical Study on the Interaction between Eperisone Hydrochloride and Human Serum Albumin Using Spectroscopic, Calorimetric, and Molecular Docking Analyses.

Eperisone hydrochloride (EH) is widely used as a muscle relaxant for patients with muscular contracture, low back pain, or spasticity. Human serum albumin (HSA) is a highly soluble negatively charged, endogenous and abundant plasma protein ascribed with the ligand binding and transport properties. The current study was undertaken to explore the interaction between EH and the serum transport protein, HSA. Study of the interaction between HSA and EH was carried by UV-vis, fluorescence quenching, circular dichroism (CD), Fourier transform infrared (FTIR) spectroscopy, Förster's resonance energy transfer, isothermal titration calorimetry and differential scanning calorimetry. Tryptophan fluorescence intensity of HSA was strongly quenched by EH. The binding constants (Kb) were obtained by fluorescence quenching, and results show that the HSA-EH interaction revealed a static mode of quenching with binding constant Kb ≈ 104 reflecting high affinity of EH for HSA. The negative ΔG° value for binding indicated that HSA-EH interaction was a spontaneous process. Thermodynamic analysis shows HSA-EH complex formation occurs primarily due to hydrophobic interactions, and hydrogen bonds were facilitated at the binding of EH. EH binding induces α-helix of HSA as obtained by far-UV CD and FTIR spectroscopy. In addition, the distance between EH (acceptor) and Trp residue of HSA (donor) was calculated 2.18 nm using Förster's resonance energy transfer theory. Furthermore, molecular docking results revealed EH binds with HSA, and binding site was positioned in Sudlow Site I of HSA (subdomain IIA). This work provides a useful experimental strategy for studying the interaction of myorelaxant with HSA, helping to understand the activity and mechanism of drug binding.

Neo-epitopes on crotonaldehyde modified DNA preferably recognize circulating autoantibodies in cancer patients.

DNA damage is one of the leading causes of various pathological conditions including carcinogenesis. Crotonaldehyde is a 4-carbon unsaturated bifunctional aldehyde which is found ubiquitously and produced both exogenously and endogenously. It reacts with deoxyguanosine and form adducts with DNA. These adducts were detected and found involved in tumor formation in rats treated with crotonaldehyde. In the present study, structural changes in DNA by crotonaldehyde were evaluated by Fourier transform infrared (FTIR) spectroscopy, differential scanning colorimetry (DSC), dynamic light scattering (DLS), high-performance liquid chromatography (HPLC), and atomic force microscopy (AFM). Enhanced binding was observed in cancer autoantibodies with the DNA modified by crotonaldehyde than the native counterpart. Immunological studies revealed enhanced binding of cancer autoantibodies with crotonaldehyde modified DNA, compared to the native form. Furthermore, lymphocyte DNA isolated from cancer patients demonstrated considerable recognition of anti-Cro-DNA IgG as compared to the DNA from healthy individuals. Therefore, we suggest that crotonaldehyde modified DNA presents unique epitopes, that may trigger autoantibody induction in cancer patients.

The pharmacological features of bilirubin: the question of the century.

This review looks at the toxicity and metabolism of bilirubin in terms of its pharmacological potential. Its role has gained importance as more research has revealed the functional significance and interrelationship between the gasotransmitters nitric oxide and carbon monoxide. The biological actions of bilirubin have mostly been characterized in the high micromolar range where toxic effects occur. However, it could also prove to be an important cytoprotector for brain tissue, which is inherently less equipped for antioxidant defense. Plasma bilirubin levels negatively correlate to a number of disease states. Higher levels of bilirubin that are still within the normal range provide a protective effect to the body. The effects on various disorders could be tested using controlled pharmacological upregulation of the molecule with animal models. At nanomolar concentrations, considerable benefits have been obtained when the molecule was delivered pharmacologically under in vitro or in vivo test conditions, particularly in neurodegenerative disorders and after tissue or organ transplantation. The induction of heme oxygenase-1 (HMOX-1) via the activation of nuclear factor erythroid 2-related factor or the use of bile pigments in the harvesting of diseased tissue are novel applications, and like every new therapy, should be used with caution. HMOX-1 is tissue specific, and in exceptional states, such as schizophrenia and specific types of renal disorder, the same therapy may have disastrous effects.

Physicochemical analysis of structural alteration and advanced glycation end products generation during glycation of H2A histone by 3-deoxyglucosone.

Advanced glycation end-products comprise a complex and heterogeneous group of compounds that have been implicated in diabetes-related complications. The importance of the Maillard reaction is depicted by the formation of reactive intermediate products known as α-oxoaldehydes, such as 3-deoxyglucosone (3-DG). This product has been found to be involved in accelerated vascular damage in diabetes. In the present study, calf thymus histone H2A was reacted with 3-DG, and the generation of advanced glycation end products was investigated by determining the degree of side chain modifications (lysine and arginine residues), Amadori products, carbonyl content, N(ε) -carboxymethyl lysine, and pentosidine using various physicochemical techniques. Moreover, fluorescence, absorbance as well as structural characteristics of glycated-H2A were comprehensively investigated. Overall, this study demonstrates structural perturbation, formation of different intermediates, and AGEs that are believed to hamper the normal functioning of H2A histone, compromising the integrity of chromatin structures and function in secondary complications of diabetes.

An insight into the biophysical characterization of insoluble collagen aggregates: implication for arthritis.

Misfolding and aggregation of proteins is involved in some of the most prevalent neurodegenerative disorders. The importance of collagen stems from the fact that it is one of the dominant component used for tissue engineering and drug delivery applications and is a major component of skin, tendon, bone and other connective tissues. A systematic investigation on the conformation of collagen at various concentrations of glyoxal is studied by various biophysical techniques such as Trp fluorescence, ANS binding, Circular dichroism (CD), ATR-FTIR, Congo red (CR) assay, Rayleigh light scattering and Turbidity measurements. At 60% (v/v) glyoxal, collagen retains native-like secondary structure, altered Trp environment and high ANS fluorescence, characteristic of molten globule (MG) state. At 80% (v/v) glyoxal, insoluble collagen aggregates are detected as confirmed by decrease in Trp and ANS fluorescence, increase in non-native ß sheet structure as evident from far-UV CD and FTIR spectra, increase in Thioflavin T fluorescence, Rayleigh light scattering, Turbidity measurements, as well as red shift in CR absorbance.

Structural characteristics of thermostable immunogenic outer membrane protein from Salmonella enterica serovar Typhi.

In this work, we explored the acid-induced unfolding pathway of non-porin outer membrane protein (OMP), an immunogenic protein from Salmonella Typhi, by monitoring the conformational changes over a pH range of 1.0-7.0 by circular dichroism, intrinsic fluorescence, ANS binding, acrylamide quenching, and dynamic light scattering. The spectroscopic measurements showed that OMP in its native state at pH 7.0 exists in more stable and compact conformation. In contrast, at pH 2.0, OMP retains substantial amount of secondary structure, disrupted side chain interactions, increased hydrodynamic radii, and nearly four-fold increase in ANS fluorescence with respect to the native state, indicating that MG state exists at pH 2.0. Quenching of tryptophan fluorescence by acrylamide further confirmed the accumulation of a partially unfolded state between native and unfolded state. The effect of pH on the conformation and thermostability of OMP points towards its heat resistance at neutral pH (T m ~ 69 °C at pH 7.0, monitored by change in MRE222 nm). Acid unfolded state was also characterized by the lack of a cooperative thermal transition. All these results suggested that acid-induced unfolded state of OMP at pH 2.0 represented the molten globule state. The chemical denaturation studies with GuHCl and urea as denaturants showed dissimilar results. The chemical unfolding experiments showed that in both far-UV CD and fluorescence measurements, GuHCl is more efficient than urea. GuHCl is characterized by low C m (~1 M), while urea is characterized by high C m (~3 M). The fully unfolded states were reached at 2 M GuHCl and 4 M urea concentration, respectively. This study adds to several key considerations of importance in the development of therapeutic agents against typhoid fever for clinical purposes.

The role of advanced glycation end products in various types of neurodegenerative disease: a therapeutic approach.

Protein glycation is initiated by a nucleophilic addition reaction between the free amino group from a protein, lipid or nucleic acid and the carbonyl group of a reducing sugar. This reaction forms a reversible Schiff base, which rearranges over a period of days to produce ketoamine or Amadori products. The Amadori products undergo dehydration and rearrangements and develop a cross-link between adjacent proteins, giving rise to protein aggregation or advanced glycation end products (AGEs). A number of studies have shown that glycation induces the formation of the ß-sheet structure in ß-amyloid protein, α-synuclein, transthyretin (TTR), copper-zinc superoxide dismutase 1 (Cu, Zn-SOD-1), and prion protein. Aggregation of the ß-sheet structure in each case creates fibrillar structures, respectively causing Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, familial amyloid polyneuropathy, and prion disease. It has been suggested that oligomeric species of glycated α-synuclein and prion are more toxic than fibrils. This review focuses on the pathway of AGE formation, the synthesis of different types of AGE, and the molecular mechanisms by which glycation causes various types of neurodegenerative disease. It discusses several new therapeutic approaches that have been applied to treat these devastating disorders, including the use of various synthetic and naturally occurring inhibitors. Modulation of the AGE-RAGE axis is now considered promising in the prevention of neurodegenerative diseases. Additionally, the review covers several defense enzymes and proteins in the human body that are important anti-glycating systems acting to prevent the development of neurodegenerative diseases.

Immunomodulatory effect of Unani polyherbal formulation - Tiryaq Wabai in mild to moderate COVID-19 patients - A randomized placebo-controlled clinical trial.

BACKGROUND: The pathogenesis of COVID-19 includes an integrated immune-inflammatory response. Modulation of host immune responses against the SARS-CoV-2 virus might be effective therapeutic management. Various Unani formulations have an immunomodulatory effect. OBJECTIVE: To explore the immunomodulatory effect and safety of Unani polyherbal drug (Tiryaq Wabai) in COVID-19 patients. MATERIALS AND METHODS: The current study was a randomized placebo-controlled clinical trial that included 92 mild to moderate COVID-19 patients randomized into two groups. The Unani formulation Tiryaq Wabai (2 gm orally once a day) was used as an intervention for 45 days, while the control group received a placebo. Both groups received standard care treatment. The primary outcome was 50% increment in absolute lymphocyte count (ALC). The secondary outcome was 50% increment in mean lymphocyte percentage, CD4 cells, and CD8 cell count. The mean increase in all the above parameters has also been studied. Relevant statistical tests were used to analyze the effect. RESULTS: A statistically significant improvement in a 50% increase in ALC (p-value, 0.004), lymphocyte percentage (p-value, 0.056), CD4 (p-value, 0.005), and CD8 cell count (p-value, 0.050) was reported. Also, a significant improvement in the mean value of the lymphocyte percentage (p-value 0.0007), ALC (p-value 0.0022), CD4 cell count (p-value 0.0025), and CD8 cell count (p-value 0.0093) was observed after the treatment. One adverse event of mild grade was reported in the placebo group. The analysis of safety parameters (LFT and KFT) was normal for both groups. CONCLUSION: In mild to moderate COVID-19 patients, Tiryaq Wabai effectively showed immunomodulatory activity by improving ALC count, lymphocyte percentage, CD4, and CD8 cell count.

Label-free and ultrasensitive electrochemical transferrin detection biosensor based on a glassy carbon electrode and gold nanoparticles.

In this study, we developed a label-free and ultrasensitive electrochemical biosensor for the detection of transferrin (Tf), an important serum biomarker of atransferrinemia. The biosensor was fabricated by using glassy carbon electrode (GCE) and modified with gold nanoparticles (AuNPs) via electroless deposition. The electrochemical characteristics of the GCE-AuNPs biosensors were characterized using cyclic voltammetry and electrochemical impedance spectroscopy analysis. Differential pulse voltammetry was used for quantitative evaluation of the Tf-antigen by recording the increase in the anodic peak current of GCE-AuNPs biosensor. The GCE-AuNPs biosensor demonstrates superior sensing performance for Tf-antigen fortified in buffer, with a wide linear range of 0.1 to 5000 µg/mL and a limit of detection of 0.18 µg/mL. The studied GCE-AuNPs biosensor showed excellent sensitivity, selectivity, long-term storage stability and simple sensing steps without pretreatment of clinical samples. This GCE-AuNPs biosensor indicates great potential for developing a Tf detection platform, which would be helpful in the early diagnosis of atransferrinemia. The developed GCE-AuNPs biosensor holds great potential in biomedical research related to point of care for the early diagnosis and monitoring of diseases associated with aberrant serum transferrin levels. These findings suggest that the GCE-AuNPs biosensor has great potential for detecting other serum biomarkers.

Fabrication of an affordable and sensitive corticosteroid-binding globulin immunosensor based on electrodeposited gold nanoparticles modified glassy carbon electrode.

Herein, we fabricated an ultrasensitive electrochemical immunosensor for the quantitative detection of corticosteroid-binding globulin (CBG). CBG is a protein that regulates glucocorticoid levels and is an important biomarker for inflammation. A decrease in CBG levels is a key biomarker for inflammatory diseases, such as septic shock. To enhance the electrochemical performance and provide a large surface area for anti-CBG immobilization, we functionalized the glassy carbon electrode surface with AuNPs. Electrochemical characterization methods including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to examine the construction of the fabricated immunosensor. The electrochemical signal demonstrated a remarkable sensitivity to the CBG antigen, with a detection range from 0.01 to 100 µg/mL and a limit of detection of 0.012 µg/mL, making it suitable for both clinical and research applications. This label-free immunosensor offers significant advantages, including high sensitivity, low detection limits and excellent selectivity, making it a promising tool for detecting CBG in complex biological samples. Its potential applications include early disease diagnosis, treatment monitoring and studying CBG-related physiological processes.

Virtual screening and site-directed mutagenesis-derived aptamers for precise Salmonella typhimurium prediction: emphasizing OmpD targeting and G-quadruplex stability.

The efficient detection of the foodborne pathogen Salmonella typhimurium has historically been hampered by the constraints of traditional methods, characterized by protracted culture periods and intricate DNA extraction processes for PCR. To address this, our research innovatively focuses on the crucial and relatively uncharted virulence factor, the Outer Membrane Protein D (OmpD) in Salmonella typhimurium. By harmoniously integrating the power of virtual screening and site-directed mutagenesis, we unveiled aptamers exhibiting marked specificity for OmpD. Among these, aptamer 7ZQS stands out with its heightened binding affinity. Capitalizing on this foundation, we further engineered a repertoire of mutant aptamers, wherein APT6 distinguished itself, reflecting unmatched stability and specificity. Our rigorous validation, underpinned by cutting-edge bioinformatics tools, amplifies the prowess of APT6 in discerning and binding OmpD across an array of Salmonella typhimurium strains. This study illuminates a transformative approach to the prompt and accurate detection of Salmonella typhimurium, potentially redefining boundaries in applied analytical chemistry and bolstering diagnostic precision across diverse research and clinical domains.Communicated by Ramaswamy H. Sarma.

Synthesis of carbon nanotubes-chitosan nanocomposite and immunosensor fabrication for myoglobin detection: An acute myocardial infarction biomarker.

The use of single-walled carbon nanotubes (SWCNTs) in biomedical applications is limited due to their inability to disperse in aqueous solutions. In this study, dispersed -COOH functionalized CNTs with N-succinylated chitosan (CS), greatly increasing the water solubility of CNTs and forming a uniformly dispersed nanocomposite solution of CNTs@CS. Coupling reagent EDC/NHS was used as a linker with the -COOH groups present on the N-succinylated chitosan which significantly improved the affinity of the CNTs for biomolecules. Myoglobin (Mb) is a promising biomarker for the precise assessment of cardiovascular risk, type 2 diabetes, metabolic syndrome, hypertension and several types of cancer. A high level of Mb can be used to diagnose the mentioned pathogenic diseases. The CNTs@CS-FET demonstrates superior sensing performance for Mb antigen fortified in buffer, with a wide linear range of 1 to 4000 ng/mL. The detection limit of the developed Mb immunosensor was estimated to be 4.2 ng/mL. The novel CNTs@CS-FET immunosensor demonstrates remarkable capability in detecting Mb without being affected by interferences from nonspecific antigens. Mb spiked serum showed a recovery rate of 100.262 to 118.55 % indicating great promise for Mb detection in clinical samples. The experimental results confirmed that the CNTs@CS-FET immunosensor had excellent selectivity, reproducibility and storage stability.

An affordable label-free ultrasensitive immunosensor based on gold nanoparticles deposited on glassy carbon electrode for the transferrin receptor detection.

In recent decades, there has been a concerning and consistent rise in the incidence of cancer, posing a significant threat to human health and overall quality of life. The transferrin receptor (TfR) is one of the most crucial protein biomarkers observed to be overexpressed in various cancers. This study reports on the development of a novel voltammetric immunosensor for TfR detection. The electrochemical platform was made up of a glassy carbon electrode (GCE) functionalized with gold nanoparticles (AuNPs), on which anti-TfR was immobilized. The surface characteristics and electrochemical behaviors of the modified electrodes were comprehensively investigated through scanning electron microscopy, XPS, Raman spectroscopy FT-IR, electrochemical cyclic voltammetry and impedance spectroscopy. The developed immunosensor exhibited robust analytical performance with TfR fortified buffer solution, showing a linear range (LR) response from 0.01 to 3000 µg/mL, with a limit of detection (LOD) of 0.01 µg/mL and reproducibility (RSD <4 %). The fabricated sensor demonstrated high reproducibility and selectivity when subjected to testing with various types of interfering proteins. The immunosensor designed for TfR detection demonstrated several advantageous features, such as being cost-effective and requiring a small volume of test sample making it highly suitable for point-of-care applications.