Human Albumin Research Articles

Structure-based discovery of a new type of scaffold compound as binding competitors for protein-bound Uremic Toxins.

Protein-bound uremic toxins (PBUTs) are the main cause of uremia, but traditional hemodialysis is ineffective in removing them because of their strong ability to bind to human serum albumin (HSA), highlighting the need for new treatments. In this study, first, structure-based docking was used to screen a diverse library of 200,376 virtual compounds against the active sites I and II. After two rounds of docking screening, 3944 candidate molecules were obtained. Second, 23 candidate molecules were obtained after ADMET prediction and toxicity analysis. Five candidate molecules were finally obtained after visual analysis and MM-PBSA calculations. We subsequently assessed their competitive displacement efficiency through a microdialysis experiment, and the results revealed that ZINC000008791789, ZINC000012297018, and ZINC000012296493 are promising binding competitors for PBUTs, as they have higher dialysis efficiency than the optimal displacer LA, approximately double the dialysis efficiency. The other two molecules, ZINC000031161007 and ZINC000004090361, although less efficient than LA, still outperformed the control group. Notably, four of them shared the same molecular scaffold, and three of them contained a flavonoid group. These findings provide a foundation for the development of more effective PBUT binding competitors, potentially benefiting uremia patients in the future.

Management of Muscle Cramps in Patients With Cirrhosis: A Systematic Review of Randomised Controlled Trials.

Muscle cramps are common in patients with cirrhosis. Despite their prevalence and impact on health-related quality of life, there are no widely used clinical practice guidelines for management of muscle cramps in cirrhosis. The aim of this review was to critically evaluate current evidence regarding treatment of muscle cramps in cirrhosis. A systematic review using PubMed, MEDLINE (Ovid), Embase, and Scopus databases was performed on 30 June by two independent reviewers to identify randomised controlled trials (RCTs) reporting interventions for muscle cramps in cirrhotic patients. Twelve RCTs evaluating 13 distinct interventions were identified. Baclofen, methocarbamol, orphenadrine, and taurine supplementation reduced cramp frequency, severity, and duration when compared to placebo. Human albumin, pregabalin, and quinidine reduced cramp frequency compared to placebo. Pickle juice reduced cramp severity compared to placebo. BCAA supplementation and calcium carbonate were found to reduce cramp frequency compared to baseline. Stretching demonstrated a signal towards reducing cramp severity and frequency, and meditation had a signal towards reducing severity only when compared to baseline. Electro-acupuncture was the only intervention which demonstrated no therapeutic effect. Pregabalin was the only agent associated with significant side effects that limited its use. Methocarbamol, orphenadrine, and taurine supplementation were found in placebo-controlled RCTs to be effective in reducing cramp frequency, severity, and duration in cirrhotic patients. All other interventions reported aside from electro-acupuncture demonstrated a positive impact on cramps. High-quality RCTs are needed to further investigate the use of these treatments in terms of comparative efficacy and safety.

Revealing the antioxidant properties of alkyl gallates: a novel approach through quantum chemical calculations and molecular docking.

This study investigates the antioxidant potential of alkyl gallates (C1-C10), focusing on the impact of alkyl chain length and solvent polarity on their antioxidant properties. Known for their biomedical relevance in mitigating oxidative stress, alkyl gallates' structure-activity relationships, particularly regarding chain length and environmental factors, still need to be explored. Key thermochemical parameters, including bond dissociation enthalpy (BDE), ionization potential (IP), proton affinity (PA), and electron transfer enthalpy (ETE), reveal that shorter alkyl chains (C1-C4) exhibit superior antioxidant activity. In contrast, longer chains (C5-C10) show reduced effectiveness due to steric hindrance and lower solubility in polar solvents. Molecular docking studies also demonstrated favorable binding interactions with vital biological targets, further reinforcing their antioxidant potential. Quantum chemical calculations were performed using Gaussian 16 with the B3LYP/6-311G(dp) basis set for geometry optimizations. Solvent effects were modeled using the integral equation formalism-polarized continuum model (IEF-PCM). Molecular docking studies were conducted using AutoDockTools 4.2, targeting Tyrosine Kinase Hck, Heme Oxygenase, and Human Serum Albumin to evaluate fundamental binding interactions. These computational methods provided insights into alkyl gallates' chemical reactivity and antioxidant efficiency, allowing for the rational design of more potent antioxidant compounds.

Matrix Metalloproteinase-Responsive Controlled Release of Self-Assembly Nanoparticles Accelerates Heart Valve Regeneration In Situ by Orchestrating Immunomodulation.

In situ tissue engineering heart valves (TEHVs) are the most promising way to overcome the defects of existing valve prostheses. Despite their promising prospects, the clinical translation of TEHVs remains a formidable challenge, mainly due to unpredictable host interactions post-implantation. An immunomodulatory idea based on hydrogel encapsulation of nanoparticle-coated heart valve scaffolds is introduced. Specifically, galactose-modified human serum albumin nanoparticles (miR-93@HSA NPs) to deliver microRNA-93 mimics are utilized, which target macrophages and induce their differentiation into the anti-inflammatory M2 subtype, fostering a conducive immune microenvironment. Matrix metalloproteinase (MMP)-responsive hydrogel is used to encapsulate the nanoparticles, enabling targeted and sustained release. Results show that the miR-93@HSA NPs exhibit excellent ability to induce macrophage polarization toward the M2 phenotype. A decellularized valve modified with hydrogel reveals MMP-response release of the miR-93@HSA NPs. In vitro, the immunomodulatory heart valve possesses good endocytocompatibility and effectively reprograms macrophages when cocultured with HUVECs or RAW264.7 macrophages. In vivo, this valve scaffold promises to mitigate early inflammatory damage and provide a pro-endothelialization niche for scaffolds' constructive remodeling. With the use of cell coculture systems and transcriptome sequencing, the mechanism of immune-modulating scaffold accelerating endothelialization is being elucidated. The immunomodulatory heart valve scaffold holds promising potential for clinical translation.

Truncated Albumins as Novel Surrogate Biomarkers in Diabetes Therapy: Epiphenomena and Potential Clinical Applications.

Aims/Hypothesis: Among various albumin posttranslational modifications (PTMs), N- and C-terminal truncations (HSA-DA and HSA-L) have also shown biomarker potential in disease states. We examined albumin truncation longitudinal trends and correlations during diabetes therapy toward possible future clinical applications. Methods: In a preliminary longitudinal therapy investigation, mass spectrometry was employed to track PTMs of human serum albumin (HSA), including glycation (GA), cysteinylation (CA or HNA1; reversible), di/trioxidation (OA or HNA2; irreversible), and truncation (TA). These modifications were correlated with ongoing therapy in four distinct subject groups: type 1 diabetes (T1DM), type 2 diabetes (T2DM), prediabetes-obesity (PDOB), and healthy controls (NORM), observed over a follow-up period extending up to 280 days. Results: Diabetes was associated with significant reduction ("deficiency") of measured albumin truncations (For HSA-DA: T2DM = 0.32 ± 0.3%, p = 2E-08; T1DM = 1.02 ± 0.4%, p = 3E-05; PDOB = 1.61 ± 0.2%, p = 0.004; compared to NORM = 2.08 ± 0.2%). Albumin truncation reduction was more striking in T2DM (HSA-DA: T2DM vs. T1DM: p = 0.004). Improvements in glycemic control and decrease of albumin glycation during diabetes therapy were associated with concomitant increase of albumin truncations toward the "healthy" normal ranges, and vice versa ("mirror image" trends). Accordingly, albumin truncation correlated inversely with albumin glycation (HSA-DA vs. GA: R = -0.53, p = 1E-09). Conclusions: The "epiphenomenon" of albumin truncation (reflecting the severity of mean hyperglycemia and also insulin resistance) can possibly provide novel, sensitive, and complementary biomarkers (e.g., via simpler HSA-DA peptide fragment immunoassays) to monitor efficacy of diabetes therapy and also progression from "healthy" to prediabetes and type 2 diabetes, highlighting potential diagnostic and prognostic utility in clinical diabetes care.

The Efficacy of Andexanet Alfa for the Reversal of Factor Xa Inhibitors Is Not Influenced by Hemodilution with Different Volume Expanders

Background: Andexanet alfa is a specific antidote for factor Xa (FXa) inhibitors. It is licensed to treat patients under FXa inhibitor therapy with life-threatening bleeding. Concomitantly, volume expanders are used to compensate for blood loss and maintain circulation. The competitive binding of andexanet to FXa inhibitors may be disrupted due to hemodilution, as shown by laboratory assays with high sample dilution. This study investigated the efficacy of andexanet for the reversal of FXa inhibitors under hemodilution. Methods: Blood from 10 healthy volunteers was anticoagulated with rivaroxaban and subsequently treated with four different volume expanders (Ringer’s solution, 4% gelatine, 5% and 20% human albumin (HA)) at two dilution levels (20% and 50%). After anticoagulation and hemodilution, andexanet was added according to the high-dose protocol. Blood samples were analyzed using a Russell’s viper venom (RVV) test on a Clot Pro® device, a thrombin generation assay, a fully automated coagulation analyzer and a chromogenic anti-FXa activity assay. Results: After anticoagulation, the median rivaroxaban concentration was 272 ng/mL (IQR 254–353). Anticoagulation with rivaroxaban caused a significant impairment of all coagulation parameters, which was further aggravated by hemodilution. After the administration of andexanet, coagulation parameters in anticoagulated samples were reversed to near baseline in all groups. Andexanet administration decreased the rivaroxaban plasma concentration in all groups to a median of <10 ng/mL. In the anticoagulated, non-hemodiluted samples, anti-FXa activity was reduced by 98%. The anti-FXa activity in the anticoagulated, hemodiluted samples was reduced by approximately 96% in the 20% diluted samples and by about 93% in the 50% diluted samples. Conclusions: Our data indicate that FXa inhibitor reversal with andexanet is about 5% less effective with 50% hemodilution than in non-hemodiluted samples.

Leveraging Ion-Ion and Ion-Photon Activation to Improve the Sequencing of Proteins Carrying Multiple Disulfide Bonds: The Human Serum Albumin Case Study.

Gas-phase sequencing of large intact proteins (>30 kDa) via tandem mass spectrometry is an inherently challenging process that is further complicated by the extensive overlap of multiply charged product ion peaks, often characterized by a low signal-to-noise ratio. Disulfide bonds exacerbate this issue because of the need to cleave both the S-S and backbone bonds to liberate sequence informative fragments. Although electron-based ion activation techniques such as electron transfer dissociation (ETD) have been proven to rupture disulfide bonds in whole protein ions, they still struggle to produce extensive sequencing when multiple, concatenated S-S bonds are present on the same large polypeptide chain. Here, we evaluate the increase in sequence coverage obtained by combining activated-ion ETD (AI-ETD) and proton transfer charge reduction (PTCR) in the analysis of 66 kDa human serum albumin, which holds 17 disulfide bridges. We also describe the combination of AI-ETD with supplemental postactivation of the ETD reaction products via higher-energy collisional dissociation─a hybrid fragmentation method termed AI-EThcD. AI-EThcD leads to a further improvement compared to AI-ETD in both the global number of cleaved backbone bonds and the number of ruptured backbone bonds from disulfide-protected regions. Our results also demonstrate that the full potential of AI-ETD and AI-EThcD is unveiled only when combined with PTCR: reduction in overlap of ion signals leads to a sequence coverage as high as 39% in a single experiment, highlighting the relevance of spectral simplification in top-down mass spectrometry of large proteins.

A three-step method for preparing cryopreserved samples of apheresis products for post-thaw analysis yields a high recovery of viable cells.

Flow cytometry protocols for counting fresh CD34+ cell samples are not ideal for cryopreserved products due to cryoprotectant cytotoxicity. For cryopreserved samples, often large volumes of hypotonic solutions, which can cause cell death, are used to remove the cryoprotectant with a post-thaw wash. We recently developed a novel multistep dilution method with subsequent flow cytometry analysis to allow for accurate and reproducible results. The previous method involved washing steps which invalidate the ability to enumerate cell recovery, and success had to be gauged solely on viability. The new method allows for assessment of total cell recovery and viable cell recovery. Apheresis products were cryopreserved in 10% DMSO at a target WBC concentration of 300 × 106/mL. Cryovials from these products were thawed at 37°C, and samples were diluted 1:2 by three additions of 1/3 sample volume using 1%-Human Albumin in Dextran 40 (10% Low Molecular Weight Dextran in 0.9% NaCl) separated by 5 min between each addition. A 1:10 dilution was performed to obtain the correct cell concentration for flow cytometric analysis resulting in a 1:20 dilution. End WBC concentrations were ~15 × 106/mL with DMSO diluted to 0.5%. Fifty-two samples were tested with this new method. Total and viable cell recoveries were calculated based on pre-cryopreservation data. Median total cell recoveries for CD34 and CD3 were >85%, while median viable cell recoveries were >75%. Cryopreserved samples can be reliably prepared for flow cytometric testing using a step-wise dilution to preserve cell integrity and robust recoveries.

Refrigerated amniotic membrane maintains its therapeutic qualities for 48 hours

During wound healing, the migration of keratinocytes is critical for wound closure. The application of amniotic membrane (AM) on wounds with challenging contexts (e.g., chronification and diabetic foot ulcer) has proven very successful. However, the use of AM for clinical practice has several restraints when applied to patients; the most important restriction is preserving AM’s therapeutic properties between its thawing and application onto the patient’s wound. Moreover, AM collection and processing requires a cleanroom, together with specialized staff and equipment, and facilities that are not usually available in many hospitals and healthcare units. In this publication, we kept previously cryopreserved AM at different temperatures (37°C, 20°C, and 4°C) in different media (DMEM high glucose and saline solution with or without human albumin) and for long incubation time periods after thawing (24 h and 48 h). HaCaT keratinocytes and TGF-β1-chronified HaCaT keratinocytes were used to measure several parameters related to wound healing: migration, cell cycle arrest rescue, and the expression of key genes and migration-related proteins. Our findings indicate that AM kept in physiological saline solution at 4°C for 24 h or 48 h performed excellently in promoting HaCaT cell migration compared to AM that had been immediately thawed (0 h). Indeed, key proteins, extracellular signal-regulated kinase (ERK) and c-Jun, were induced by AM at 4°C in saline solution. Similarly, cell proliferation and different genes related to survival, inflammation, and senescence had, in all cases, the same response as to standard AM. These data suggest that the handling method in saline solution at 4°C does not interfere with AM’s therapeutic properties.

Functional interleukin-4 releasing microparticles impact THP-1 differentiated macrophage phenotype

IntroductionMacrophage cell therapies offer potential treatment in inflammatory diseases due to their ability to mobilize and stimulate their environment. However, successful treatment requires a pro-regenerative macrophage phenotype to be retained in vivo. Polymeric microparticles may provide a potential route to direct and sustain macrophage phenotype. Interleukin-4 (IL-4) is the most commonly used cytokine for in vitro modulation towards M2a macrophage phenotype. We designed IL-4 encapsulated microparticles to investigate the impact of drug release kinetics and developed a robust human peripheral blood monocyte cell (THP-1) in vitro assay to assess functional IL-4 release upon macrophage phenotype.MethodsIL-4 was encapsulated with human serum albumin (HSA) in microparticles fabricated from a blend of PLGA and a PLGA-PEG-PLGA triblock copolymer. Functional release of IL-4 and HSA over different time periods was measured using ELISAs. THP-1 differentiated macrophages were cultured either in direct contact with microparticles or indirectly through transwells. The immunomodulatory impact of microparticles on THP-1 cells were measured using ELISA and qPCR.Results and DiscussionIL-4 release kinetics fit with the first-order release kinetics model, indicating concentration dependent release. IL-4/HSA encapsulated microparticles modulated THP-1 differentiated macrophages towards pro-immunoregulatory subgroups. This strategy provides a novel approach in drug carrier development for in vitro assessments of macrophage phenotype to inform development of targeted therapies for inflammation and immune modulation.

Serum oxidative markers and delta neutrophil index in hyperemesis gravidarum

Objectives: To evaluate the relationship between different serum oxidative markers and the delta neutrophil index and hyperemesis gravidarum. Methods: One hundred pregnant women were enrolled in the study and divided into two groups. Group 1 included 50 women with hyperemesis gravidarum, while Group 2 (control group) included 50 pregnant women similar in age, gestational week, and body mass index. Serum oxidative markers and complete blood count inflammatory markers were compared. Results: Native thiol and total thiol were significantly lower in the Group 1 when compared with the control group (P=0.029 for native thiol; P=0.035 for total thiol). Moreover, ischemia-modified albumin (IMA) and catalase values were significantly higher in the Group 1 than in the control group (P=0.023 for IMA; P=0.021 for catalase). Index1% shows the disulfide/native thiol percent ratio and means that the Group 1 oxidant load is increased but not statistically significant. Myeloperoxidase, ferroxidase, and the delta neutrophil index did not differ significantly between the two groups (P=0.591, P=0.793, and P=0.52; respectively). Conclusions: According to our study, contrary to the literature, although there are differences in some values, when evaluated individually hyperemesis gravidarum does not impose an extra burden on maternal oxidant-antioxidant balance.

The Significance of Albumin Concentration and some of its Altered Forms in Iraqi Patients with Chronic Hepatitis B Virus

Background: The liver synthesizes albumin, a pivotal protein with approximately 60-65% of total plasma proteins. During ischemic attacks linked to oxidative stress, reactive oxygen species, and acidosis, the properties of albumin undergo alterations. This leads to generation of ischemia-modified albumin, which is characterized by a diminished metal-binding capacity, particularly for transition metals like copper, nickel, and cobalt. Objectives: This study aimed to assess the significance of serum albumin and ischemia-modified albumin concentrations in Iraqi individuals with hepatitis B virus Methods: A case control study consisted of 50 patients with hepatitis B were recruited from Gastroenterology hospital in the Medical city/ Baghdad/ Iraq, during the period January to February in 2023, The patients group included males and females; whose ages ranged from 18 years to 77 years with a mean value 44 year. Meanwhile the study group consisted of 50 age- and sex-matched normal healthy individuals. Albumin concentration was determined in the serum samples, using a Biosystems kit, and ischemia modified albumin concentration were measured through the albumin cobalt binding test. The ischemia modified albumin/ [albumin] ratio and Ischemia modified albumin index were then calculated. Statistical Analysis: results were reported as a mean value ± standard deviation. The differences were considered highly significant if (p < (0.001), and significant where (p = (0.002) and (p = (0.033) Results: lower serum albumin concentration was measured in the patients group, while the mean value of ischemia modified albumin concentration in the patients' group and healthy control were 0.466 ± 0.114 absorbance unit & 0.395 ± 0.070 absorbance unit, respectively, with a statistically significant increase (P < 0.001). The ischemia modified albumin ratio in the hepatitis B patients and control groups were 0.172 ± 0.073 and 0.117 ± 0.050, respectively, showing a significant increase as well (P < 0.001). Additionally, the ischemia modified albumin index in the patients and the control groups were 0.491 ± 0.167 & 0.390 ± 0.131, respectively, with a statically significant increase (p<0.001) in the patients group. Conclusion: In the patients’ group with hepatitis B, serum albumin concentration is decreased, while the level of ischemia modified albumin, ischemia modified albumin ratio, and ischemia modified albumin index are increased. The elevation in ischemia modified albumin, ischemia modified albumin ratio, and ischemia modified albumin index were more prominent in younger patients and those with albumin concentration less than 4g/dl. Moreover, the prevalence of hepatitis B is higher in men compared to women.

Computational Analysis of Interactions Between Drugs and Human Serum Albumin.

Drug molecules exist as complexed with serum proteins such as human serum albumin (HSA) and/or unbound free form in the blood circulation. Drugs can be effective only when they are free. Thus, it is important to understand aspects that are important for interaction between drugs and interacting proteins. In this study, interactions among 2990 FDA approved drugs and HSA were computational analyzed to unravel principles that are critical for drug-HSA interactions. Docking results showed that drugs have higher affinity toward cavity-1 (C1) than cavity-2 (C2). A total of 1131 drug molecules have docking score greater than 60 while 768 molecules have docking score greater than 60 when they are docked in C2. In addition, three solvent channels have potential to direct solvent to C1 cavity while C2 does not have any effective channel. The post MD analyses demonstrated that drugs are making polar interactions with basic amino acids in the binding cavities. Verbscoside and ceftazidime both have stable low RMSD values throughout MD simulation with 2 Å on average in C1 cavity. The ligand RMSD shows less stability for verbscoside, which is around 4 Å when it is in complex with HSA in C1. The individual contribution of the residues K192, K196, R215, and R254 to ceftazidime are -1.92 ± 0.18, -3.09 ± 0.09, -2.17 ± 0.17, and - 2.32 ± 0.098, respectively. These residues contribute the binding energy of the verbscoside by -6.06 ± 0.08, -2.10 ± 0.06, and - 1.57 ± 0.03 kcal/mol individually in C1 cavity. C2 is making polar interactions with drug via R469, K472, and K488 residues and their contribution to the two drugs are -3.13 ± 0.21 kcal/mol for R469, -1.94 ± 0.18 kcal/mol for K472, and -1.96 ± 0.11 kcal/mol for K488 to total binding energy of ceftazidime. The binding energy of verbscoside is 57.17 ± 7.00 kcal/mol and Arg-407 has the highest contribution this bind energy individually with -4.29 ± 0.12 kcal/mol. Drugs with hydrogen bond donor/acceptor chemical adducts such as verbscoside involve higher hydrogen bond formation in C1 pocket. Ceftazidime makes interaction with HSA toward hydrophobic residues, L384, L404, L487, and L488 in the C2 cavity.

Biophysical insight into the interaction mechanism of 4-bromo-N-(thiazol-2- yl)benzenesulfonamide and human serum albumin using multi-spectroscopic and computational studies

4-Bromo-N-(thiazol-2-yl)benzenesulfonamide (1) is enriched with bioactive components and is highlighted for its pharmacological properties. However, its pharmacokinetic characteristics are yet to be reported. The interaction of compound 1 with carrier proteins in the bloodstream is an important factor that affects its potential therapeutic efficacy. This study aimed to elucidate the pharmacokinetic mechanisms of compound 1 in relation to human serum albumin (HSA) using multi-spectroscopic and computational techniques. Its predicted drug-like properties revealed no mutagenicity, although potential hepatotoxicity and interactions with certain cytochrome P450 enzymes were observed. Spectroscopic analyses extensively provided the interaction between HSA and 1 through a static fluorescence quenching mechanism with spontaneous hydrophobic interactions and hydrogen bonding. The binding constant of the HSA‒1 complex was relatively moderate to strong at a level of 106 M−1. Various spectroscopic techniques including ultraviolet-visible, Fourier-transform infrared, and circular dichroism spectroscopies indicated that its binding induced alteration in the α-helix content of HSA. Competitive binding and molecular docking studies designated the preferential binding of 1 to sub-structural domain IIA binding site I of HSA. Molecular dynamic simulations further illustrated the formation of a stable complex between 1 and HSA, accompanied by conformational changes in the protein. Importantly, esterase capacity of the HSA‒1 complex increased compared to the free HSA. Therefore, elucidation of the HSA‒1 binding mechanism provides valuable insights into the pharmacokinetics, suggesting potential benefits for the further development of 1 as a therapeutic agent.

A theranostic photosensitizer-conjugated albumin co-loading with resiquimod for cancer-targeted imaging and robust photo-immunotherapy

Cancer immunotherapy remains a low immune response rate in clinic because of dominant immunosuppressive tumor microenvironment (TME) and lack of effective drug to specifically remodel the TME. In this work, we introduced a tumor-seeking human serum albumin (HSA) based delivery platform by covalently conjugating with a tumor-targeting near-infrared (NIR) photosensitizer (IR-DBI) and non-covalently loading of immune modulator Resiquimod (R848). HSA exhibited tumor-preferential accumulation after covalent conjugation with IR-DBI. Meanwhile, HSA restricted the rotation of IR-DBI, narrowed the HOMO-LUMO energy gap, significantly enhanced fluorescent intensity and dual-modal phototherapy (PTT/PDT). The enhanced phototherapeutic effect further induced robust ICD effect. More importantly, non-covalent loading of R848 could be released from HSA at tumor sites by laser irradiation-induced heat. The in-situ release of R848 in TME efficiently promoted the maturation of DC cells and repolarized M2 macrophages to M1 macrophages. Consequently, robust photo-induced antitumor immunity was triggered in the different mice models bearing primary and distant tumors or lung metastasis, which was further enhanced by combining with CTLA-4 blockade therapy. Taken together, this work may present a versatile albumin composite which exhibits tumor-preferential accumulation and imaging-guided PDT/PTT/immunotherapy.

Lapachol, a natural food component, interacts with human serum albumin: Insights of its impact on the pharmacokinetics of clinically used drugs

Lapachol (LAP), a natural 1,4-naphthoquinone used in popular medicine of South American, is an antioxidant and antimicrobial compound used as a food additive; however, its interactive profile with the main protein carrier of compounds in the human bloodstream (human serum albumin, HSA) was not still characterized. Additionally, the impact of LAP in binding clinically drugs to albumin is still unknown. Thus, the present work describes the interaction HSA:LAP using different biophysical techniques, i.e., 1H saturation-transfer difference nuclear magnetic resonance (1H STD-NMR), isothermal titration calorimetry (ITC), steady-state and time-resolved fluorescence measurements combined with molecular docking calculations. LAP interacts with subdomain region IIA (site I), mainly driven by enthalpy effects, while subdomain region IB (site III) was identified as the second binding site, mainly driven by entropy effects. The binding is spontaneous, strong (binding constant average, Kaverage ≈ 4.45 × 105 M−1), and there is a positive cooperativity in the presence of ibuprofen, with the LAP structure fully buried into the protein cavities. Overall, LAP might impact the residence time (pharmacokinetic profile) of drugs that bind to subdomains regions IIA and IB of albumin, e.g., warfarin, phenylbutazone, diflunisal, naproxen, camptothecin, doxorubicin, daunorubicin, suramin, and tyrosine kinase inhibitors.

Impact of pH-Dependent Dynamics of Human Serum Proteins on Dialysis Membranes: Cryptographic Structure Assessment, Synchrotron Imaging of Membrane-Protein Adsorption, and Molecular Docking Studies

Proteins are fundamental to biochemical processes and critical in hemodialysis. This study investigates the impact of pH on human serum albumin (HSA), fibrinogen (FB), and transferrin (TRF) interactions with polyarylethersulfone (PAES) hemodialysis membranes. A multi-method approach was utilized, including protein crystallography for structural insights, hydration layer analysis to explore solvation and interaction potentials, molecular docking using AutoDock 4.0 for binding affinity simulations, and in-situ X-ray synchrotron SR-μCT imaging to observe protein deposition dynamics.Molecular docking revealed that PAES demonstrated superior binding energies and interaction patterns with FB and TRF compared to cellulose triacetate (CTA), facilitated by specific hydrogen bonding within a water shell. CTA displayed weaker, hydration-sensitive interactions varying with pH. Imaging studies indicated that FB showed higher adsorption at pH 6 than at pH 7.2, predominantly in the middle membrane regions. Similarly, HSA and TRF exhibited increased adsorption at pH 6, suggesting a stronger affinity under acidic conditions. Mixed protein solutions also indicated higher adsorption at pH 6, emphasizing an increased risk of membrane fouling.These findings highlight the crucial role of pH in modulating protein-membrane interactions and enhancing the efficacy of hemodialysis. A deeper understanding of hydration environments and their effects on protein binding affinities provides valuable insights for optimizing membrane design and performance. Clinically, this research suggests that fine-tuning pH during hemodialysis could mitigate protein fouling on membranes, thereby improving procedural efficiency and potentially leading to better patient outcomes through enhanced dialysis effectiveness.

In Vitro Cytotoxicity and Mechanistic Investigation of Quinazolin-4(1H)-One Linked Coumarin as a Potent Anticancer Agent.

Quinazolinone-coumarin conjugates synthesized through Late-Stage Functionalization approach are evaluated for their invitro biological activity for 60 human cancer cell lines representing nine different cancer types. Among the synthesized compounds, eight displayed significant growth inhibitory activity across a spectrum of cancer types, with compound 23 demonstrating particularly notable cytotoxicity. Further investigation involved a five-dose assay of compound 23 against NCI-60 cancer cell lines, revealing its efficacy at different concentrations. Additionally, binding studies elucidated its interaction with Human Serum Albumin (HSA) and DNA. The results indicated a strong binding affinity of 23 with HSA, evidenced by a high binding constant (2.26 × 105 M-1). Moreover, its interaction with DNA occurred via intercalation, specifically between the base pairs of DNA strands, with a binding constant of 5.51 × 104 M-1. This suggests that compound 23 has the ability to bind to both DNA and transport proteins, making it a promising pharmacophore with potential therapeutic applications.

Exploring the interaction of hesperetin-mediated green synthesised gold and silver nanoparticles with human serum albumin: A comparative analysis

Exploring the interaction of hesperetin-mediated green synthesised gold and silver nanoparticles with human serum albumin: A comparative analysis

Dairy and nondairy proteins as nano-architecture structures for delivering phenolic compounds: Unraveling their molecular interactions to maximize health benefits.

Phenolic compounds are recognized for their benefits against degenerative diseases. Clinical and nutritional applications are limited by their low solubility, stability, and bioavailability, compromising their efficacy. Natural macromolecules, such as lipids, polysaccharides, and proteins, employed as delivery systems can efficiently overcome these limitations. In this sense, proteins are attractive due to their biocompatibility and dynamic structure properties, functional adaptability and self-assembly capabilities, offering stability, efficient encapsulation, and controlled release. This review explores the potential use of dairy proteins, caseins, and whey proteins, and, alternatively, nondairy proteins, gelatin, human serum albumin, maize zein, and soybean proteins, in building wall materials for the delivery of phenolic compounds. To optimize performance, aspects, such as protein-phenolic affinity and complex stability/activity, should be considered when designing particle nano-architecture. Molecular interactions between protein-phenolic compound complexes are, thus, further discussed, as well as the effects of temperature and pH and strategies to stabilize and preserve nano-architecture and retain phenolic compound activity. All proteins harbor one or more putative binding sites, shared or not, depending on the phenolic compound. Preservation techniques are still a case-to-case study, as no behavior patterns among different complexes are noted. Safety aspects necessary for the marketing of nanoproducts, such as characterization, toxicity assessments, and post-market monitoring as defined by the European Food Safety Authority and the Food and Drug Administration, are discussed, evidencing the need for a unified regulation. This review broadens our understanding and opens new opportunities for the development of novel protein-based nanocarriers to obtain more effective and stable products, enhancing phenolic compound delivery and health benefits.