Showing papers on "Human serum albumin published in 2015"
TL;DR: This probe and the quantitative ratiometric photoacoustic pH imaging method are shown to have high safety, be easy-to-operate, and have depth-independent accuracy for real-time in vivo pH imaging of entire tumors.
Abstract: A photoacoustic nanoprobe is self-assembled from human serum albumin and two types of dye molecules, one is inert to pH and the other is pH sensitive. This probe and the quantitative ratiometric photoacoustic pH imaging method are shown to have high safety, be easy-to-operate, and have depth-independent accuracy for real-time in vivo pH imaging of entire tumors. These features make them promising for future cancer prognosis and therapeutic planning.
229 citations
TL;DR: HSA-IR780 NPs may serve as a promising substitute for IR780 in further clinical PDT and PTT, as determined by increased temperature and enhanced generation of singlet oxygen after laser irradiation at a wavelength of 808 nm.
203 citations
TL;DR: A pronounced difference in the protein corona is observed depending on the type of characterization technique applied, as the biological identity of a particle is given by theprotein corona.
Abstract: Here we demonstrate how a complementary analysis of nanocapsule–protein interactions with and without application media allows gaining insights into the so called hard and soft protein corona. We have investigated how both human plasma and individual proteins (human serum albumin (HSA), apolipoprotein A-I (ApoA-I)) adsorb and interact with hydroxyethyl starch (HES) nanocapsules possessing different functionalities. To analyse the hard protein corona we used sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and a protein quantitation assay. No significant differences were observed with regards to the hard protein corona. For analysis of the soft protein corona we characterized the nanocapsule-protein interaction with isothermal titration calorimetry (ITC) and dynamic light scattering (DLS). DLS and ITC measurements revealed that a high amount of plasma proteins were adsorbed onto the capsules’ surface. Although HSA was not detected in the hard protein corona, ITC measurements indicated the adsorption of an HSA amount similar to plasma with a low binding affinity and reaction heat. In contrast, only small amounts of ApoA-I protein adsorb to the capsules with high binding affinities. Through a comparison of these methods we have identified ApoA-I to be a component of the hard protein corona and HSA as a component of the soft corona. We demonstrate a pronounced difference in the protein corona observed depending on the type of characterization technique applied. As the biological identity of a particle is given by the protein corona it is crucial to use complementary characterization techniques to analyse different aspects of the protein corona.
184 citations
TL;DR: This review will cover fatty acid chain and posttranslational modifications of HSA that potentially modulate how HSA interacts with various pharmacological drugs, including glycation, cysteinylation, S-nitrosylation,S-transnitrosation and S-guanylation.
Abstract: Human serum albumin (HSA) regulates the transport and availability of numerous chemical compounds and molecules in the blood vascular system. While previous HSA research has found that HSA interacts with specific varieties of ligands, new research efforts aim to expand HSA's ability to interact with more different drugs in order to improve the delivery of various pharmacological drugs. This review will cover fatty acid chain and posttranslational modifications of HSA that potentially modulate how HSA interacts with various pharmacological drugs, including glycation, cysteinylation, S-nitrosylation, S-transnitrosation and S-guanylation.
176 citations
TL;DR: The hybrid nanoflower-based IMER was applicable to the digestion of a complex human sample, showing great promise for proteome analysis and the residual activity of the nanoflowers decreased slightly even after eight repeated use, demonstrating promising stability.
Abstract: A facile approach for the synthesis of enzyme–inorganic hybrid nanoflowers and their application as an immobilized α-chymotrypsin (ChT) reactor (IMER) for highly efficient protein digestion was described. The hybrid nanoflowers were room-temperature synthesized in aqueous solution using calcium phosphate (Ca3(PO4)2) as the inorganic component and ChT as the organic component. The effects of reaction parameters on the formation of the enzyme-embedded hybrid nanoflowers and their growth mechanism were investigated systematically. By monitoring the reaction of N-benzoyl-L-tyrosine ethyl ester (BTEE), the enzymatic activity of the immobilized ChT was calculated and the results showed 266% enhancement in enzymatic activity. The performance of such a nanoreactor was further demonstrated by digesting bovine serum albumin (BSA) and human serum albumin (HSA), with a stringent threshold for unambiguous identification of these digests, the yielding sequence coverages for nanoflower-based digestion were 48% and 34%, higher than those obtained with the free enzyme. The digestion time of BSA and HSA in the former case was less than 2 min, about 1/360 of that performed in the latter case (12 h). Furthermore, the residual activity of the nanoflowers decreased slightly even after eight repeated use, demonstrating promising stability. In addition, the hybrid nanoflower-based IMER was applicable to the digestion of a complex human sample, showing great promise for proteome analysis.
145 citations
TL;DR: AlX-0061 represents a minimized bispecific biotherapeutic of 26 kDa, nearly six times smaller than monoclonal antibodies, and is supportive of clinical development in RA.
Abstract: The pleiotropic cytokine interleukin-6 (IL-6) plays an important role in the pathogenesis of different diseases, including rheumatoid arthritis (RA). ALX-0061 is a bispecific Nanobody® with a high affinity and potency for IL-6 receptor (IL-6R), combined with an extended half-life by targeting human serum albumin. We describe here the relevant aspects of its in vitro and in vivo pharmacology. ALX-0061 is composed of an affinity-matured IL-6R-targeting domain fused to an albumin-binding domain representing a minimized two-domain structure. A panel of different in vitro assays was used to characterize the biological activities of ALX-0061. The pharmacological properties of ALX-0061 were examined in cynomolgus monkeys, using plasma levels of total soluble (s)IL-6R as pharmacodynamic marker. Therapeutic effect was evaluated in a human IL-6-induced acute phase response model in the same species, and in a collagen-induced arthritis (CIA) model in rhesus monkeys, using tocilizumab as positive control. ALX-0061 was designed to confer the desired pharmacological properties. A 200-fold increase of target affinity was obtained through affinity maturation of the parental domain. The high affinity for sIL-6R (0.19 pM) translated to a concentration-dependent and complete neutralization of sIL-6R in vitro. In cynomolgus monkeys, ALX-0061 showed a dose-dependent and complete inhibition of hIL-6-induced inflammatory parameters, including plasma levels of C-reactive protein (CRP), fibrinogen and platelets. An apparent plasma half-life of 6.6 days was observed after a single intravenous administration of 10 mg/kg ALX-0061 in cynomolgus monkeys, similar to the estimated expected half-life of serum albumin. ALX-0061 and tocilizumab demonstrated a marked decrease in serum CRP levels in a non-human primate CIA model. Clinical effect was confirmed in animals with active drug exposure throughout the study duration. ALX-0061 represents a minimized bispecific biotherapeutic of 26 kDa, nearly six times smaller than monoclonal antibodies. High in vitro affinity and potency was demonstrated. Albumin binding as a half-life extension technology resulted in describable and expected pharmacokinetics. Strong IL-6R engagement was shown to translate to in vivo effect in non-human primates, demonstrated via biomarker deregulation as well as clinical effect. Presented results on preclinical pharmacological properties of ALX-0061 are supportive of clinical development in RA.
132 citations
TL;DR: This study will be helpful to understand the binding mechanism of cytosine β-D arabinofuranoside with HSA and associated alterations and help understand the topology of protein in absence and presence of drug.
130 citations
TL;DR: This study characterizes the formation of a PC on AgNPs and demonstrates its influence on cytotoxicity and cell activation through a cell surface receptor.
125 citations
TL;DR: The impressively high imprinting factor reached, exceeding 20, strongly confirmed that semi-covalent imprinting resulted in formation of a large number of very well defined molecular cavities with high affinity to the HSA molecules.
118 citations
TL;DR: Structural data unambiguously prove that cisplatin mainly binds to His105 and Met329 side chains; additional binding sites are detected at His288, Met298, and Met548 and at His535, His67 and His247.
111 citations
TL;DR: The zeta potential results suggested that both hydrophobic and electrostatic interactions played important roles in the protein–metformin complex formation.
Abstract: The interaction between metformin and human serum albumin (HSA), as well as its glycated form (gHSA) was investigated by multiple spectroscopic techniques, zeta potential, and molecular modeling under physiological conditions. The steady state and time-resolved fluorescence data displayed the quenching mechanism of HSA-metformin and gHSA-metformin was static. The binding information, including the binding constants, number of binding sites, effective quenching constant showed that the binding affinity of metformin to HSA was greater than to gHSA which also confirmed by anisotropy measurements. It was determined that metformin had two and one set of binding sites on HSA and gHSA, respectively. Far-UV CD spectra of proteins demonstrated that the α-helical content decreased with increasing metformin concentration. The zeta potential and resonance light scattering (RLS) diagrams provided that lower drug concentration induced metformin aggregation on gHSA surface as compare to HSA. The increase in polarizability was one of the important factors for the enhancement of RLS and the formation of drug/protein complexes. The zeta potential results suggested that both hydrophobic and electrostatic interactions played important roles in the protein-metformin complex formation. Site marker experiments and molecular modeling showed that the metformin bound to subdomain IIIA (Sudlow's site II) on HSA and gHSA.
TL;DR: The efficiency of HSA to scavenge the free radical ions was increased in the presence of TQ which is generated in the body by various metabolic processes.
Abstract: Thymoquinone (TQ) is the main constituent of Nigella sativa and is traditionally used as a folk medicine Our aim was to investigate the binding mechanism of TQ to human serum albumin (HSA) isoforms (‘N’ form at pH 74 and ‘B’ form at pH 90) using biophysical methods such as intrinsic tryptophan fluorescence quenching, isothermal titration calorimetry (ITC), circular dichroism (CD), dynamic light scattering (DLS), Forster resonance energy transfer (FRET) and antioxidant activity in the absence and presence of TQ We have calculated the binding and thermodynamic parameters from spectroscopic and calorimetric methods CD and DLS were respectively used to monitor the changes in the secondary structure and hydrodynamic radii of HSA as a result of its interaction with TQ The esterase and antioxidant or radical scavenging activities of both the isoforms of HSA were investigated in the absence/presence of TQ The antioxidant activity of TQ was remarkably enhanced upon its interaction with HSA Therefore, the efficiency of HSA to scavenge the free radical ions was increased in the presence of TQ which is generated in the body by various metabolic processes
TL;DR: DP-TPPNa was successfully applied for the quantitative detection of BSA in fetal bovine serum and the mechanism of fluorescent turn-on behavior was elucidated utilizing an unfolding process induced by guanidine hydrochloride, which revealed a capture process via selective hydrophobic interaction and hydrogen bonding between luminogen and SA.
Abstract: An aggregation-enhanced emission active luminogen named as sodium 4,4′4″-(3,4-diphenyl-1H-pyrrole-1,2,5-triyl)tribenzoate (DP-TPPNa) with propeller construction was synthesized and developed as a “turn on” fluorescent probe for in situ quantitation of albumin in blood serum. The DP-TPPNa fluorescence intensity was linearly correlated with the concentration of two serum albumins, bovine serum albumin (BSA) and human serum albumin (HSA), in pure PBS buffer in the ranges of 2.18–70 and 1.68–100 μg/mL, respectively. The detection limits were as low as 2.18 μg/mL for BSA and 1.68 μg/mL for HSA. The response time of fluorescence to serum albumin (SA) was very short (below 6 s), which achieved real-time detection. It also showed high selectivity to SA because other components in serum barely interfere with the detection of DP-TPPNa to SA, enabling in situ quantitative detection of SA without isolation from serum. DP-TPPNa was successfully applied for the quantitative detection of BSA in fetal bovine serum. The m...
TL;DR: This Letter presents a simple and nondestructive approach to quantify the protein concentration in the protein-NPs aqueous solution using circular dichroism (CD) spectroscopy.
Abstract: Considerable efforts have been made to synthesize and characterize protein–nanoparticle conjugates (protein–NPs) for their promising applications in bionanotechnology. However, protein concentration determination in the protein–NPs has so far not been reported. In this Letter, we present a simple and nondestructive approach to quantify the protein concentration in the protein–NPs aqueous solution using circular dichroism (CD) spectroscopy. Carbon dots (∼4 nm), gold nanoparticles (∼10 nm), and polyethylene glycol (PEG, molecular weight ∼3000) were either physically mixed or covalently conjugated (not in the case of gold nanoparticles) with proteins (human transferrin, human serum albumin, and ovalbumin). We were able to quantify the protein concentration in the protein–nanoparticle conjugates using a calibration curve from the CD spectra.
TL;DR: Thermodynamic investigations revealed the interaction between the two carotenoids and HSA/BSA is synergistically driven by enthalpy and entropy, and hydrophobic forces and electrostatic attraction have a significant role in the reactions.
TL;DR: The targeted NPs showed increased cytotoxic activity in liver tumor cells compared to the nontargeted NPs, and the DOX/GA-rHSA NPs could be considered as an efficient nanoplatform for targeting drug delivery system for liver cancer.
Abstract: Due to overexpression of glycyrrhetinic acid (GA) receptor in liver cancer cells, glycyrrhetinic acid modified recombinant human serum albumin (rHSA) nanoparticles for targeting liver tumor cells may result in increased therapeutic efficacy and decreased adverse effects of cancer therapy. In this study, doxorubicin (DOX) loaded and glycyrrhetinic acid modified recombinant human serum albumin nanoparticles (DOX/GA-rHSA NPs) were prepared for targeting therapy for liver cancer. GA was covalently coupled to recombinant human serum albumin nanoparticles, which could efficiently deliver DOX into liver cancer cells. The resultant GA-rHSA NPs exhibited uniform spherical shape and high stability in plasma with fixed negative charge (∼-25 mV) and a size about 170 nm. DOX was loaded into GA-rHSA NPs with a maximal encapsulation efficiency of 75.8%. Moreover, the targeted NPs (DOX/GA-rHSA NPs) showed increased cytotoxic activity in liver tumor cells compared to the nontargeted NPs (DOX/rHSA NPs, DOX loaded recombinant human serum albumin nanoparticles without GA conjugating). The targeted NPs exhibited higher cellular uptake in a GA receptor-positive liver cancer cell line than nontargeted NPs as measured by both flow cytometry and confocal laser scanning microscopy. Biodistribution experiments showed that DOX/GA-rHSA NPs exhibited a much higher level of tumor accumulation than nontargeted NPs at 1 h after injection in hepatoma-bearing Balb/c mice. Therefore, the DOX/GA-rHSA NPs could be considered as an efficient nanoplatform for targeting drug delivery system for liver cancer.
TL;DR: Interestingly in the case of 3,4-O-dicaffeoyl-1,5-γ-quinide, it is observed the entrance of two ligand molecules in the same binding site, leading up to a first dissociation constant even in the hundred nanomolar range, which is to the authors' knowledge the highest affinity ever observed for HSA and its ligands.
TL;DR: The results exclusively highlight the fact that it is the hydrophobic character of the bile salt that governs the extent of interaction with the Protein-bile salt aggregates and is found to be reduced in comparison to that of the native protein.
Abstract: The present study demonstrates a detailed characterization of the interaction of a series of bile salts, sodium deoxycholate (NaDC), sodium cholate (NaC), and sodium taurocholate (NaTC), with a model transport protein, human serum albumin (HSA). Here, steady-state and time-resolved fluorescence spectroscopic techniques have been used to characterize the interaction of the bile salts with HSA. The binding isotherms constructed from steady-state fluorescence intensity measurements demonstrate that the interaction of the bile salts with HSA can be characterized by three distinct regions, which were also successfully reproduced from the significant variation of the emission wavelength (λem) of the intrinsic tryptophan (Trp) moiety of HSA. The time-resolved fluorescence decay behavior of the Trp residue of HSA was also found to corroborate the steady-state results. The effect of interaction with the bile salts on the native conformation of the protein has been explored in a circular dichroism (CD) study, which...
TL;DR: The binding constants and free energy corresponding to experimental and computational analysis suggest that there are hydrophobic and hydrophilic interactions when piperine binds to HSA and AGP and prove that the HSA–piperine complex is stable in nature.
Abstract: Human serum albumin (HSA) and α-1-acid glycoprotein (AGP) (acute phase protein) are the plasma proteins in blood system which transports many drugs. To understand the pharmacological importance of ...
TL;DR: This human serum albumin-based codelivery system represents a promising platform for combination chemotherapy in breast cancers and exhibited significantly lower side effects regarding bone marrow suppression and organ and gastrointestinal toxicities.
Abstract: In our study, we aimed to develop a codelivery nanoparticulate system of pirarubicin (THP) and paclitaxel (PTX) (Co-AN) using human serum albumin to improve the therapeutic effect and reduce systemic toxicities. The prepared Co-AN demonstrated a narrow size distribution around 156.9 ± 3.2 nm (PDI = 0.16 ± 0.02) and high loading efficiency (87.91 ± 2.85% for THP and 80.20 ± 2.21% for PTX) with sustained release profiles. Significantly higher drug accumulation in tumors and decreased distribution in normal tissues were observed for Co-AN in xenograft 4T1 murine breast cancer bearing BALB/c mice. Cytotoxicity test against 4T1 cells in vitro and antitumor assay on 4T1 breast cancer in vivo demonstrated that the antitumor effect of Co-AN was superior to that of the single drug or free combination. Also, Co-AN induced increased apoptosis and G2/M cell cycle arrest against 4T1 cells compared to that of the single drug formulation. Remarkably, Co-AN exhibited significantly lower side effects regarding bone marrow suppression and organ and gastrointestinal toxicities. This human serum albumin-based codelivery system represents a promising platform for combination chemotherapy in breast cancers.
TL;DR: The structural alterations in the HSA after binding to the taurine were demonstrated by exploiting various biophysical techniques and molecular docking study deciphered the possible residues involved in protein and drug interaction.
TL;DR: It is shown for the first time that absence of albumin is characterised by worse systemic hemodynamics, renal function and higher mortality in a rodent model of chronic liver failure and illustrates the important non-oncotic properties ofalbumin in protecting against endothelial dysfunction.
TL;DR: The detailed study of the thermodynamics of the drug-protein interaction process from isothermal titration calorimetric (ITC) experiments is found to unfold the signature of electrostatic as well as hydrophobic interaction forces underlying the binding process.
Abstract: Herein, the binding interaction of a potential chemotherapeutic antibacterial drug norfloxacin (NOF) with a serum transport protein, human serum albumin (HSA), is investigated. The prototropic transformation of the drug (NOF) is found to be remarkably modified following interaction with the protein as manifested through significant modulations of the photophysics of the drug. The predominant zwitterionic form of NOF in aqueous buffer phase undergoes transformation to the cationic form within the protein-encapsulated state. This implies the possible role of electrostatic interaction force in NOF–HSA binding. This postulate is further substantiated from the effect of ionic strength on the interaction process. To this end, the detailed study of the thermodynamics of the drug–protein interaction process from isothermal titration calorimetric (ITC) experiments is found to unfold the signature of electrostatic as well as hydrophobic interaction forces underlying the binding process. Thus, interplay of more than...
TL;DR: In this article, differently shaped and surface functionalized TiO2 anatase nanoparticles and human serum albumin were selected to study protein-nanoparticles interaction both in a solu...
Abstract: In this investigation, differently shaped and surface functionalized TiO2 anatase nanoparticles and human serum albumin (HSA) were selected to study protein-nanoparticles interaction both in a solu...
TL;DR: The impact of covalent bonds on the protein structure is greater than that of the electrostatic force.
Abstract: Protein–nanoparticle interactions are important in biomedical applications of nanoparticles and for growing biosafety concerns about nanomaterials. In this study, the interactions of four plasma proteins, human serum albumin (HSA), myoglobin (MB), hemoglobin (HB), and trypsin (TRP), with Au and Ag nanoparticles were investigated by FT-IR spectroscopy. The secondary structure of thio-proteins changed with time during incubation with Au and Ag nanoparticles, but the secondary structures of non-thio-proteins remained unchanged. The incubation time for structural changes depended on the sulfur–metal bond energy; the stronger the sulfur–metal energy, the less the time needed. H/D exchange experiments revealed that protein–NP complexes with thio-proteins were less dynamic than free proteins. No measurable dynamic differences were found between free non-thio-proteins and the protein–Au (or Ag) nanoparticle complex. Therefore, the impact of covalent bonds on the protein structure is greater than that of the electrostatic force.
TL;DR: Thermodynamic investigations reveal that the hydrogen bonding and van der Waals force are the major binding forces in the binding of (+)-catechin to HSA, and fluorescence experiments suggest that (+)- catechin can quench the fluorescence of HSA through a static quenching mechanism.
Abstract: In this study, the interaction between (+)-catechin and human serum albumin (HSA) was investigated using isothermal titration calorimetry (ITC), in combination with fluorescence spectroscopy, UV-vis absorption spectroscopy, and circular dichroism (CD) spectroscopy. Thermodynamic investigations reveal that the hydrogen bonding and van der Waals force are the major binding forces in the binding of (+)-catechin to HSA. The binding of (+)-catechin to HSA is driven by favorable enthalpy and unfavorable entropy. Fluorescence experiments suggest that (+)-catechin can quench the fluorescence of HSA through a static quenching mechanism. The obtained binding constants and the equilibrium fraction of unbound (+)-catechin show that (+)-catechin can be stored and transported from the circulatory system to reach its target organ. Binding site I is found to be the primary binding site for (+)-catechin. Additionally, as shown by the UV-vis absorption, synchronous fluorescence spectroscopy and circular dichroism (CD) spectroscopy, (+)-catechin may induce conformational and microenvironmental changes of HSA.
TL;DR: In this paper, the association constants and thermodynamic parameters for the interaction of HSA with pheophytin from Talinum triangulare were studied by UV-Vis absorption, fluorescence techniques, and molecular modeling (docking).
Abstract: In the North of Brazil (Para and Amazonas states) the leaves of the plant Talinum triangulare (popular: cariru) replace spinach as food. From a phytochemical point of view, they are rich in compounds of the group of pheophytins. These substances, related to chlorophyll, have photophysical properties that give them potential application in photodynamic therapy. Human serum albumin (HSA) is one of the main endogenous vehicles for biodistribution of molecules by blood plasma. Association constants and thermodynamic parameters for the interaction of HSA with pheophytin from Talinum triangulare were studied by UV-Vis absorption, fluorescence techniques, and molecular modeling (docking). Fluorescence quenching of the HSA's internal fluorophore (tryptophan) at temperatures 296 K, 303 K, and 310 K, resulted in values for the association constants of the order of 10⁴ L∙mol(-1), indicating a moderate interaction between the compound and the albumin. The negative values of ΔG° indicate a spontaneous process; ΔH° = 15.5 kJ∙mol(-1) indicates an endothermic process of association and ΔS° = 0.145 kJ∙mol(-1)∙K(-1) shows that the interaction between HSA and pheophytin occurs mainly by hydrophobic factors. The observed Trp fluorescence quenching is static: there is initial non-fluorescent association, in the ground state, HSA:Pheophytin. Possible solution obtained by a molecular docking study suggests that pheophytin is able to interact with HSA by means of hydrogen bonds with three lysine and one arginine residues, whereas the phytyl group is inserted in a hydrophobic pocket, close to Trp-214.
TL;DR: Under physiological and pathological conditions, HSA has a pivotal role in heme scavenging transferring the metal-macrocycle from high- and low-density lipoproteins to hemopexin, thus acquiring globin-like reactivity.
Abstract: Human serum albumin (HSA): (i) controls the plasma oncotic pressure, (ii) modulates fluid distribution between the body compartments, (iii) represents the depot and carrier of endogenous and exogenous compounds, (iv) increases the apparent solubility and lifetime of hydrophobic compounds, (v) affects pharmacokinetics of many drugs, (vi) inactivates toxic compounds, (vii) induces chemical modifications of some ligands, (viii) displays antioxidant properties, and (ix) shows enzymatic properties. Under physiological and pathological conditions, HSA has a pivotal role in heme scavenging transferring the metal-macrocycle from high- and low-density lipoproteins to hemopexin, thus acquiring globin-like reactivity. Here, the heme-based catalytic properties of HSA are reviewed and the structural bases of drug-dependent allosteric regulation are highlighted.
TL;DR: The interaction of Tenofovir with human serum albumin (HSA) under physiological conditions was examined by a combined experimental and computational approach and indicated that hydrophobic interaction plays a major role in the Ten-HSA complex.
TL;DR: Three-dimensional fluorescence and circular dichroism results showed that the binding of CEF can cause conformational and some microenvironmental changes of HSA, which is of great importance in pharmacology and pharmacodynamics.