(albumin human )
- Molecular mechanism of the binding of 3,4,5-tri-O-caffeoylquinic acid to human serum albumin: Saturation transfer difference NMR, multi-spectroscopy, and docking studies. [Journal Article]
- JPJ Photochem Photobiol B 2016 Oct 17; 165:24-33
- As a natural dietary polyphenol, 3,4,5-tri-O-caffeoylquinic acid (3,4,5-triCQA) exhibits numerous stronger pharmacological activities than that of its analogues. Studies on interaction between 3,4,5-...
As a natural dietary polyphenol, 3,4,5-tri-O-caffeoylquinic acid (3,4,5-triCQA) exhibits numerous stronger pharmacological activities than that of its analogues. Studies on interaction between 3,4,5-triCQA and protein are very helpful for understanding the mechanism of these enhanced biological functions. In this study, (1)H saturation transfer difference NMR ((1)H STD-NMR) combined with multi-spectroscopy were used to probe the interaction of 3,4,5-triCQA with human serum albumin (HSA). Both qualitative and quantitative (1)H STD-NMR indicated that 3,4,5-triCQA can specifically bind to HSA at the favored Sudlow's site II with caffeoyl groups as the main recognizable moiety. Fluorescence emission spectra showed that Stern-Volmer quenching constant (KSV) decreases from 10.132×10(4)M(-1) to 9.711×10(4)M(-1) with temperature raise, indicating that 3,4,5-triCQA quenches HSA fluorescence through a static mechanism. Binding constant (Kb=5.557×10(5)M(-1)) and the number of binding sites (n≈1) at 298K suggested that 3,4,5-triCQA only occupies one site in HSA with high affinity. Enthalpy (ΔH=-28.802kJ/mol) and entropy (ΔS=12.429J/mol/K) change proved the dominant role of electrostatic interaction in binding process. Multi-spectroscopic analysis also confirmed that the protein secondary structure and hydrophobicity were significantly affected. Molecular docking further verified the NMR and spectroscopic results. Overall, 3,4,5-triCQA exhibited a strong albumin affinity owing to the plural caffeoyl groups, which lead to the enhanced pharmacological activities. This study clarified the molecular mechanism of 3,4,5-triCQA in binding to HSA, and the findings are beneficial for the research on polyphenol-like drugs and antioxidants in foods or cosmetics.
- Quenching of fluorescence by meclizine, a probe study for structural and conformational changes in human serum albumin. [Journal Article]
- JBJ Biomol Struct Dyn 2016 Oct 21; :1-44
- The goal of this study was to investigate the interactions between meclizine (MEC) and human serum albumin (HSA) under physiological conditions by different spectroscopies and molecular modeling tech...
The goal of this study was to investigate the interactions between meclizine (MEC) and human serum albumin (HSA) under physiological conditions by different spectroscopies and molecular modeling technique. The drug, MEC quenched the intrinsic fluorescence of HSA and the analysis of the results revealed that static quenching mechanism. The binding of MEC quenches the HSA fluorescence; stoichiometry was 1:1 interaction. Thermodynamic quantities were calculated at different temperatures suggested that hydrophobic and van der Waals interaction with HSA-MEC. The molecular distance, r, between donor and acceptor was estimated according to Forster's theory of non-radiation energy transfer. CD and FT-IR studies confirm changes of secondary structure of HSA. Molecular docking studies validate MEC molecule interact to HSA in sub domain IIA.
- Risk Factors for the Development and Progression of Diabetic Kidney Disease in Patients with Type 2 Diabetes Mellitus and Advanced Diabetic Retinopathy. [Journal Article]
- DMDiabetes Metab J 2016 Sep 20
- CONCLUSIONS: The prevalence of DKD was about 60% in patients with T2DM and advanced DR. HbA1c variability and TG/HDL-C ratio may affect the development and progression of DKD in these patients.
- PEGylated Human Serum Albumin: Review of PEGylation, Purification and Characterization Methods. [Review]
- APAdv Pharm Bull 2016; 6(3):309-317
- Human serum albumin (HSA) is a non-glycosylated, negatively charged protein (Mw: about 65-kDa) that has one free cystein residue (Cys 34), and 17 disulfide bridges that these bridges have main role i...
Human serum albumin (HSA) is a non-glycosylated, negatively charged protein (Mw: about 65-kDa) that has one free cystein residue (Cys 34), and 17 disulfide bridges that these bridges have main role in its stability and longer biological life-time (15 to 19 days). As HSA is a multifunctional protein, it can also bind to other molecules and ions in addition to its role in maintaining colloidal osmotic pressure (COP) in various diseases. In critical illnesses changes in the level of albumin between the intravascular and extravascular compartments and the decrease in its serum concentration need to be compensated using exogenous albumin; but as the size of HSA is an important parameter in retention within the circulation, therefore increasing its molecular size and hydrodynamic radius of HSA by covalent attachment of poly ethylene glycol (PEG), that is known as PEGylation, provides HSA as a superior volume expander that not only can prevent the interstitial edema but also can reduce the infusion frequency. This review focuses on various PEGylation methods of HSA (solid phase and liquid phase), and compares various methods to purifiy and characterize the pegylated form.
- Octyl gallate: An antioxidant demonstrating selective and sensitive fluorescent property. [Journal Article]
- FCFood Chem 2017 Mar 15; 219:268-273
- Octyl gallate (OG) is an internationally recognized antioxidant that demonstrates selective and sensitive fluorescent property. The fluorescence of OG can be selectively enhanced in the presence of h...
Octyl gallate (OG) is an internationally recognized antioxidant that demonstrates selective and sensitive fluorescent property. The fluorescence of OG can be selectively enhanced in the presence of human serum albumin (HSA) and bovine serum albumin (BSA). The specific structures of HSA and BSA provided the basic conditions for fluorescence enhancement. OG yielded approximately 49- and 11-fold increments in emission intensity in the presence of HSA and BSA at a molar ratio of 1:1, respectively. The lifetimes of HSA and BSA correspondingly decreased. A Förster resonance energy transfer phenomenon occurred during interaction between OG and HSA or BSA. Our in-depth investigation of OG-HSA interaction showed that formation of a stable complex was an important prerequisite to efficiently enhance the fluorescence of OG. The selective and sensitive fluorescent property of OG can possibly be used to determine OG concentration via the standard addition method, which must be performed under certain conditions.
- Bioavailable estradiol concentrations are elevated and predict mortality in septic patients: a prospective cohort study. [Journal Article]
- CCCrit Care 2016 Oct 21; 20(1):335
- CONCLUSIONS: Contrary to our hypothesis, bioavailable estradiol levels were elevated in sepsis patients, particularly nonsurvivors, and were independently associated with mortality. Whether estradiol's effects are harmful, beneficial, or neutral in septic patients remains unknown, but our findings raise caution about estradiol's therapeutic potential in this setting. Our findings do not provide an explanation for sex-based differences in sepsis incidence and outcomes.
- Fibrillogenesis of human serum albumin in the presence of levodopa - spectroscopic, calorimetric and microscopic studies. [Journal Article]
- IJInt J Biol Macromol 2016 Oct 12; 94(Pt A):301-308
- Studying amyloid associated neurodegenerative diseases is an active area of research. Cure for these diseases are still to be discovered. In the present study we have performed comprehensive biophysi...
Studying amyloid associated neurodegenerative diseases is an active area of research. Cure for these diseases are still to be discovered. In the present study we have performed comprehensive biophysical and computational experiments showing levodopa not only significantly inhibits heat induced fibrillization of human serum albumin but also disaggregates preformed fibrils. Thioflavin T (ThT) binding assay was used to monitor the fibrillation process of human serum albumin (HSA) at 65°C in the presence and absence of levodopa. Binding of levodopa was studied using isothermal titration calorimetry (ITC), binding constant was found to be 3.6×10(3)M(-1). Thermal stabilization effect of levodopa on HSA was studied using differential scanning calorimetry (DSC). Microscopic imaging techniques were employed to analyze the morphology of aggregates and effect of levodopa on aggregation. Further, molecular docking study was also utilized to decipher the amino acid residues involved in the binding interaction of levodopa with HSA. Levodopa interferes in the Fibrillogenesis of HSA by interacting with the amino acid residues near to drug binding site II on the HSA with the binding constant of the order of 10(3) and stabilizes the protein. The results are indicative of the potential use of levodopa as a therapeutic agent for the treatment of amyloid diseases.
- Human serum albumin as vehicle for the solubilization of perylene diimides in aqueous solutions. [Journal Article]
- IJInt J Biol Macromol 2016 Oct 6; 94(Pt A):246-257
- The chemical, physical and photophysical properties of perylene diimides have attracted substantial attention for the potential applications in diverse fields ranging from advanced materials to biome...
The chemical, physical and photophysical properties of perylene diimides have attracted substantial attention for the potential applications in diverse fields ranging from advanced materials to biomedical applications. Some applications require the diimides to be in aqueous environment where they tend to dissolve poorly. We investigated the use of human serum albumin as a vehicle to increase the aqueous exposure of monomeric perylene diimides. Since studies on the interactions of these compounds with protein is scarce we characterized the binding and the possible effects on the protein. In order to increase the affinity of the dyes to the protein we have used perylene diimides with substituents that replicate the side chains of natural amino acids. The results show that only the dyes containing the side chain of leucine and phenylalanine yield measurable binding. Only the phenylalanine analogue promotes energy transfer with the lone tryptophan residue of albumin indicating different binding modalities for the dyes. In addition, this analogue is the only one which shows photochemical activity that prompts its release from the protein upon laser irradiation.
- Determination of collagen type IV by Surface Plasmon Resonance Imaging using a specific biosensor. [Journal Article]
- ABAnal Biochem 2016 Dec 15; 515:40-46
- Serum collagen type IV (COLIV) is a promising tumor marker. High COLIV concentrations have been found in the serum of patients with colorectal, gastric, lung, liver and breast cancers. The aim of thi...
Serum collagen type IV (COLIV) is a promising tumor marker. High COLIV concentrations have been found in the serum of patients with colorectal, gastric, lung, liver and breast cancers. The aim of this work was to develop a biosensor for use with the Surface Plasmon Resonance Imaging (SPRI) technique for COLIV determination. The biosensor consists of glass covered with gold and immobilized monoclonal mouse anti-human collagen type IV antibody via cysteamine linker. The biosensor works selectively within a dynamic response range between 10 and 300 ng mL(-1), with LOD 2.4 ng mL(-1) and LOQ 8 ng mL(-1). The precision of determination is 4.7% at a 150 ng mL(-1) COLIV spike and 8.0% at a 20 ng mL(-1) spike, with recoveries of 101% and 106% respectively. A 100-fold excess of collagen I, albumin, laminin and fibronectin is tolerated. The average COLIV blood plasma concentration of healthy donors determined by the developed method was 69 ± 10 ng mL(-1), while the median of six results available in the literature was approximately 80 ng mL(-1). The average COLIV blood plasma concentration of breast cancer patients was 360 ± 68 ng mL(-1), showing the high potential of COLIV as a marker of this type of cancer.
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- Assessment of the interaction procedure between Pt(IV) prodrug [Pt(5,5'-dmbpy)Cl4 and human serum albumin: Combination of spectroscopic and molecular modeling technique. [Journal Article]
- JBJ Biomol Struct Dyn 2016 Oct 21; :1-9
- In this study, a cytotoxic Pt(IV) complex [Pt(5,5'-dmbpy)Cl4 (5,5'-dmbpy is 5,5'-dimethyl-2,2'-bipyridine) was selected to investigate its affinity to human serum albumin (HSA) by spectroscopy and mo...
In this study, a cytotoxic Pt(IV) complex [Pt(5,5'-dmbpy)Cl4 (5,5'-dmbpy is 5,5'-dimethyl-2,2'-bipyridine) was selected to investigate its affinity to human serum albumin (HSA) by spectroscopy and molecular docking methods. This complex has a bidentate nitrogen donor ligand with four chloride anions attached to a Pt(IV) metal in a distorted octahedral environment. The ﬂuorescence data showed this complex quench the intrinsic ﬂuorescence of HSA through a static quenching mechanism. The binding constant (Kb) and the number of binding sites (n) were obtained based on the results of fluorescence measurements. UV-vis, circular dichroism spectroscopy, and three-dimensional fluorescence spectroscopy proved that the Pt(IV) complex could slightly change the secondary structure of protein. Thermodynamic parameters show that the Pt(IV) complex binds to HSA through electrostatic and Vander Waals interactions with one binding site. The molecular docking results confirmed the spectroscopic results and showed that Pt(IV) complex is embedded into subdomain IIA of protein. The aim of this study is to describe the performance of effective anti-cancer drugs when faced with proteins such as HSA.