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albumin human [keywords]
- Glycolaldehyde and maleyl conjugated human serum albumin as potential macrophage-targeting carriers for molecular imaging purposes. [JOURNAL ARTICLE]
- Contrast Media Mol Imaging 2014 Apr 22.
Maleylated bovine serum albumin is a known ligand for targeting macrophages and has potential as a carrier for molecular imaging purposes. We present a novel synthesis of glycolaldehyde-conjugated human serum albumin (GA-HSA) and maleylated human serum albumin (Mal-HSA). Seventeen modifications of fluorescently tagged GA-HSA and Mal-HSA molecules with different degrees of conjugation were prepared. The comparative uptake studies, using 12 of these modifications, were done in vitro on mouse monocytes/macrophages (RAW264.7), and evaluated qualitatively by confocal microscopy and quantitatively by flow cytometry. The GA modifications are taken up by the macrophages approximately 40% better than the maleyl modifications at low concentrations (≤3 μm), while at higher concentrations it appears that the maleyl modifications are taken up around 25-44% better than the GA-modified HSA. However, high uptake at low concentrations will be beneficial for in vivo localizing inflammation in areas with low penetration of the probe as in an atherosclerotic plaque. Further, another advantage of GA-HSA is that GA competes less than the maleyl group for the free reactive amine sites that are to be used for conjugation of metal chelating ligands (e.g. tetraazacyclododecanetetraacetic acid and triazacyclononanetriacetic acid). Metal ions such as Gd(3+) and Mn(2+) can be chelated for positive Magnetic Resonance (MR) contrast and positron emitting ions such as (64) Cu(2+) and (68) Ga(3+) for Positron Emission Tomography (PET) imaging. These are important properties, especially, when considering the MR contrast possibilities owing to the low sensitivity of the technique, and would motivate the use of GA-HSA before Mal-HSA. © 2014 The Authors. Contrast Media & Molecular Imaging published by John Wiley & Sons, Ltd.
- Structural studies of bovine, equine, and leporine serum albumin complexes with naproxen. [JOURNAL ARTICLE]
- Proteins 2014 Apr 17.
Serum albumin, a protein naturally abundant in blood plasma, shows remarkable ligand binding properties of numerous endogenous and exogenous compounds. Most of serum albumin binding sites are able to interact with more than one class of ligands. Determining the protein-ligand interactions among mammalian serum albumins is essential for understanding the complexity of this transporter. We present three crystal structures of serum albumins in complexes with naproxen (NPS): bovine (BSA-NPS), equine (ESA-NPS), and leporine (LSA-NPS) determined to 2.58 Å (C2), 2.42 Å (P61 ) and 2.73 Å (P21 21 21 ) resolutions, respectively. A comparison of the structurally investigated complexes with the analogous complex of human serum albumin (HSA-NPS) revealed surprising differences in the number and distribution of naproxen binding sites. Bovine and leporine serum albumins possess three NPS binding sites, but ESA has only two. All three complexes of albumins studied here have two common naproxen locations, but BSA and LSA differ in the third NPS binding site. None of these binding sites coincides with the naproxen location in the HSA-NPS complex, which was obtained in the presence of other ligands besides naproxen. Even small differences in sequences of serum albumins from various species, especially in the area of the binding pockets, influence the affinity and the binding mode of naproxen to this transport protein. © Proteins 2014;. © 2014 Wiley Periodicals, Inc.
- Toward the understanding of the environmental effects on core ionizations. [JOURNAL ARTICLE]
- J Comput Chem 2014 Apr 18.
Experimental X-ray absorption spectra are extensively used to determine electronic structure of small molecules but remain difficult to exploit for proteins due to the large number of peaks within their spectra. For such complex systems, theoretical tools like quantum mechanics/molecular mechanics methodology can greatly ease the assignment of the spectra. This study presents a systematic methodology to evaluate core-ionization energies (Eion ) in proteins with the help of the asymptotic projection approach (Glushkov and Tsaune, Z. Vichislit. Matem. Mat. Fiz. 1985, 25, 298; Glushkov, Chem. Phys. Lett. 1997, 273, 122; Glushkov, Chem. Phys. Lett. 1998, 287, 189; Glushkov, J. Math. Chem. 2002, 31, 91; Glushkov, Opt. Spectrosc. 2002, 93, 15). An in-depth inspection of Eion of systems of increasing complexity is considered, going from amino acids to polyglycine and to glycine in human serum albumin (HSA). Computational analysis can help to better understand experimental data and to discriminate environmental effects by tracing them back to individual and collective electrostatic contributions. In the present work, it was found that Eion of alpha carbon of glycine residues in HSA ranges from 285 to 295 eV depending on their surroundings. © 2014 Wiley Periodicals, Inc.
- A facile sol-gel synthesis of impurity-free nanocrystalline titania. [JOURNAL ARTICLE]
- Phys Chem Chem Phys 2014 Apr 22.
This paper reports an original technique that provides a highly pure crystalline sol of titania with controllable particle size by ultrasonic activation of the hydrolysis products of titanium isopropoxide in an aqueous medium at a near-neutral pH, which is potentially promising in impurity-sensitive electronics and biochemical engineering. Optimal conditions (H2O/TIP ratio, sonication time, etc.) for preparation of stable nanocrystalline titania sol were adopted. A new mechanism of regulation of aggregation and polycondensation under ultrasonic irradiation is proposed. Entrapment of human serum albumin (HSA) in the formed porous titania matrix results in high thermal stability of the protein dopants: the denaturation temperature of HSA is shifted by 31 °C.
- Selective and sensitive detection of free bilirubin in blood serum using human serum albumin stabilized gold nanoclusters as fluorometric and colorimetric probe. [JOURNAL ARTICLE]
- Biosens Bioelectron 2014 Apr 8.:370-376.
We report here a fluorescence quenching based non-enzymatic method for sensitive and reliable detection of free bilirubin in blood serum samples using human serum albumin (HSA) stabilized gold nanoclusters (HSA-AuNCs) as fluorescent probe. The fluorescence of the nanoclusters was strongly quenched by bilirubin in a concentration dependent manner by virtue of the inherent specific interaction between bilirubin and HSA. A strong binding constant of 0.55×10(6)Lmole(-1) between the HSA-AuNC and bilirubin was discerned. The nano clusters each with size ~1.0nm (in diameter) and a core of Au18 were homogeneously distributed in HSA molecules as revealed from the respective high resolution transmission electron microscopic and mass spectroscopic studies. The fluorescence quenching phenomena which obeyed a simple static quenching mechanism, was utilized for interference free detection of bilirubin with minimum detection limit (DL) of 248±12nM (S/N=3). The fluorescence response of HSA-AuNCs against bilirubin was practically unaltered over a wide pH (6-9) and temperature (25-50°C) range. Additionally, peroxidase-like catalytic activity of these nanoclusters was exploited for colorimetric detection of bilirubin in serum sample with a DL of 200±19nM by following the decrease in absorbance (at λ440nm) of the reaction and its rate constant (Kp) of 2.57±0.63mLμg(-1)min(-1). Both these fluorometric and colorimetric methods have been successfully used for detection of free bilirubin in blood serum samples.
- Human Serum Albumin, Systemic Inflammation And Cirrhosis. [REVIEW]
- J Hepatol 2014 Apr 18.
Human serum albumin (HSA) is one of the most frequent treatments in patients with decompensated cirrhosis. Prevention of paracentesis-induced circulatory dysfunction, prevention of type-1 HRS associated to bacterial infections and treatment of type-1 hepatorenal syndrome are the main indications. In these indications treatment with HSA is associated to improvement in survival. Albumin is a stable and very flexible molecule with a heart shape, 585 residues and three domains of similar size, each one containing two sub-domains. Many of the physiological functions of HSA rely on its ability to bind an extremely wide range of endogenous and exogenous ligands, to increase their solubility in plasma, to transport them to specific tissues and organs or to dispose of them when they are toxic. The chemical structure of albumin can be altered by some specific processes (oxidation, glication) leading to rapid clearance and catabolism. An outstanding feature of HSA is its capacity to bind lypopolysaccharide and other bacterial producs (lypoteichoic acid and peptidoglican), reactive oxygen species, nitric oxide and other nitrogen reactive species and prostaglandins. Binding to NO and prostaglandins are reversible, so they can be transferred to other molecules at different sites from their synthesis. Through these functions, HSA modulates the inflammatory reaction. Decompensated cirrhosis is a disease associated systemic inflammation, which plays an important role in the pathogenesis of organ or system dysfunction/failure. Although, the beneficial effects of HAS have been traditionally attributed to plasma volume expansion, they could also relate to its effects modulating systemic and organ inflammation.
- Antiviral Effects of Persimmon Extract on Human Norovirus and Its Surrogate, Bacteriophage MS2. [JOURNAL ARTICLE]
- J Food Sci 2014 Apr 17.
Human noroviruses (NoVs) are the leading cause of gastroenteritis and foodborne illnesses worldwide. In this study, we investigated the effects of persimmon extract (PE) on NoV GII.4 and bacteriophage MS2. We also examined the relationship between the tannin content of PE and its antiviral effects to identify the active ingredient in PE. Different persimmon tannin (PT) solutions were prepared by mixing PE with different concentrations of bovine serum albumin. The antiviral efficacy of these solutions against NoV was evaluated by quantifying the amount of residual noroviral genome using a quantitative reverse transcription PCR (qRT-PCR) assay. The antiviral efficacy of PE against MS2 was examined with an infectivity assay (plaque assay). Solutions containing ≥0.11 mg/mL PT reduced the noroviral genome by more than 70.0% and the infectivity of MS2 by more than 2.5 log PFU/mL. However, the effects of PT on both viruses decreased markedly at a concentration of 0.08 mg/mL and solutions containing negligible PT had no antiviral activity. These results suggest that the PT component of PE inactivates NoV and MS2. Our results indicate that PE is a nontoxic antiviral agent effective against enteric viruses.
- Serological changes induced by blend of sunset yellow, metanil yellow and tartrazine in swiss albino rat, rattus norvegicus. [Journal Article]
- Toxicol Int 2014 Jan; 21(1):65-8.
The present study was carried out to evaluate the toxic effect of blend of some food colors on Swiss albino rats.A blend (1:1:1) of sunset yellow, metanil yellow and tartrazine showed additive effects on serological parameters which indicate that addition of these dye together in food stuff may give rise to more toxic effects than are produced by each dye individually. Animals were divided into four groups (I, II, III, and IV). First group was treated as control and respective group of animals received 25, 50 and 75 mg/kg body weight blend of food colors by gavaging up to 30 days.The serological study showed a decrease in total protein and albumin and an increase in alkaline phosphatase, SGPT and total bilirubin. The results revealed that oral administration of these blend did not affect the body weight gain.The prolonged consumption of the blend may cause adverse effect on human health.
- Carnitine in severely disabled patients: Relation to anthropometric, biochemical variables, and nutritional intake. [JOURNAL ARTICLE]
- Brain Dev 2014 Apr 16.
Background: Carnitine plays a pivotal role in a variety of cellular functions. Carnitine deficiency often occurs in severely disabled patients, especially under valproic acid administration. However, the possible causative factors underlying carnitine deficiency have not been fully identified. The present study aimed at clarifying the association of various anthropometric and biochemical variables, including dietary intake of carnitine, with carnitine levels in severely disabled patients. Methods: Twenty-six severely disabled patients (mean age: 14.1years; s.d. 7.8) were enrolled. Plasma carnitine levels were evaluated by an enzyme cycling assay. Estimation of the dietary intake of carnitine was made based on dietary records over a 3-day period. Results: Plasma total and free carnitine levels in patients were significantly lower than those in controls obtained from the previous report. However, the ratios of free carnitine to total carnitine did not change significantly. Free carnitine levels were well correlated with a nutritional intake of carnitine. Administration of not only valproic acid but also other anti-epileptic drugs was found to cause a significant decrease of free carnitine levels after adjusting the nutritional intake of carnitine. Among various anthropometric or biochemical variables, albumin and uric acid showed a significant correlation with free carnitine levels. Conclusions: Physicians should be aware of the fact that severely disabled patients are at risk for carnitine deficiency even in the absence of valproic acid administration, and pay more attention to the nutritional intake of carnitine.
- AN INSIGHT INTO THE BINDING MECHANISM OF IMIPENEM TO HUMAN SERUM ALBUMIN BY SPECTROSCOPIC AND COMPUTATIONAL APPROACHES. [JOURNAL ARTICLE]
- Mol Pharm 2014 Apr 17.
The mechanism of interaction between imipenem and HSA was investigated by various techniques like fluorescence, UV-Vis absorbance, FRET, circular dichroism, urea denaturation, enzyme kinetics, ITC and molecular docking. We found that imipenem binds to HSA at a high affinity site located in sub-domain IIIA (Sudlow's site I) and a low affinity site located in sub-domain IIA-IIB. Electrostatic interactions played a vital role along with hydrogen bonding and hydrophobic interactions in stabilizing imipenem-HSA complex at sub-domain IIIA, while only electrostatic and hydrophobic interactions were present at sub-domain IIA-IIB. The binding and thermodynamic parameters obtained by ITC showed that the binding of imipenem to HSA was a spontaneous process ( = -32.31 kJ mol-1 for high affinity site and = -23.02 kJ mol-1 for low affinity site) with binding constants in the range of 104-105 M-1. Spectroscopic investigation revealed only one binding site of imipenem on HSA (Ka~104 M-1). FRET analysis showed that the binding distance between imipenem and HSA (Trp-214) was optimal (r = 4.32 nm) for quenching to occur. Decrease in esterase-like activity of HSA in the presence of imipenem showed that Arg-410 and Tyr-411 of sub-domain IIIA (Sudlow's site II) were directly involved in the binding process. CD spectral analysis showed altered conformation of HSA upon imipenem binding. Moreover, the binding of imipenem to sub-domain IIIA (Sudlow's site II) of HSA also affected its folding pathway as clear from urea-induced denaturation studies.