scholarly journals Systematic FTIR Spectroscopy Study of the Secondary Structure Changes in Human Serum Albumin under Various Denaturation Conditions

Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 359 ◽  
Author(s):  
Usoltsev ◽  
Sitnikova ◽  
Kajava ◽  
Uspenskaya
Keyword(s):  
Secondary Structure ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Ftir Spectroscopy ◽  
Conformational Changes ◽  
Data Interpretation ◽  
Random Coil ◽  
Helical Conformation ◽  
Structure Changes

Human serum albumin (HSA) is the most abundant protein in blood plasma. HSA is involved in the transport of hormones, fatty acids, and some other compounds, maintenance of blood pH, osmotic pressure, and many other functions. Although this protein is well studied, data about its conformational changes upon different denaturation factors are fragmentary and sometimes contradictory. This is especially true for FTIR spectroscopy data interpretation. Here, the effect of various denaturing agents on the structural state of HSA by using FTIR spectroscopy in the aqueous solutions was systematically studied. Our data suggest that the second derivative deconvolution method provides the most consistent interpretation of the obtained IR spectra. The secondary structure changes of HSA were studied depending on the concentration of the denaturing agent during acid, alkaline, and thermal denaturation. In general, the denaturation of HSA in different conditions is accompanied by a decrease in α-helical conformation and an increase in random coil conformation and the intermolecular β-strands. Meantime, some variation in the conformational changes depending on the type of the denaturation agent were also observed. The increase of β-structural conformation suggests that HSA may form amyloid-like aggregates upon the denaturation.

scholarly journals β-Carboline Silver Compound Binding Studies with Human Serum Albumin: A Comprehensive Multispectroscopic Analysis and Molecular Modeling Study

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Ali Alsalme ◽  
Rais Ahmad Khan ◽  
Arwa M. Alkathiri ◽  
Mohd. Sajid Ali ◽  
Sartaj Tabassum ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Secondary Structure ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Conformational Changes ◽  
Neurological Diseases ◽  
Binding Studies ◽  
Parkinson’S Diseases ◽  
Circular Dichroïsm

β-Carbolines (βCs) belong to the naturally occurring alkaloid family, derived from 9H-pyrido[3,4-b]indole, also known as norharmane (Hnor). Knowing the importance of the βCs alkaloid family in biological processes, a comprehensive binding study is reported of four Ag(I) compounds containing the ligand Hnor and having different counteranions, namely, NO3−, ClO4−, BF4−, and PF6−, with human serum albumin (HSA) as a model protein. Different approaches like UV-visible, fluorescence spectroscopy, circular dichroism (CD), and molecular docking studies have been used for this purpose. The fluorescence results establish that the phenomenon of binding of Ag(Hnor) complexes to HSA can be deduced from the static quenching mechanism. The results showed a significant binding propensity of the used Ag(I) compounds towards HSA. The role of the counteranion on the binding of Ag(I) compounds to HSA appeared to be remarkable. Compounds with (ClO4−) and (NO3−) were found to have the most efficient binding towards HSA as compared to BF4−and PF6−. Circular dichroism (CD) studies made clear that conformational changes in the secondary structure of HSA were induced by the presence of Ag(I) compounds. Also, the α-helical structure of HSA was found to get transformed into a β-sheeted structure. Interestingly, (ClO4−) and (NO3−) compounds were found to induce most substantial changes in the secondary structure of HSA. The outcome of this study may contribute to understanding the propensity of proteins involved in neurological diseases (such as Alzheimer’s and Parkinson’s diseases) to undergo a similar transition in the presence of Ag-β-carboline compounds.

scholarly journals FTIR Spectroscopy Study of the Secondary Structure Changes in Human Serum Albumin and Trypsin under Neutral Salts

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 606 ◽  
Author(s):  
Dmitrii Usoltsev ◽  
Vera Sitnikova ◽  
Andrey Kajava ◽  
Mayya Uspenskaya
Keyword(s):  
Secondary Structure ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Ftir Spectroscopy ◽  
Amyloid Fibrils ◽  
Protein Structures ◽  
Helical Structure ◽  
Neutral Salt ◽  
Porcine Pancreas

The effect of neutral salts on protein conformation was first analyzed by Hofmeister in 1888, however, even today this phenomenon is not completely understood. To clarify this effect, we studied changes in the secondary structure of two proteins: human serum albumin with predominantly α-helical structure and porcine pancreas β-trypsin with the typical β-structural arrangement in aqueous solutions of neutral salts (KSCN, KCl, (NH4)2SO4). The changes in the secondary structure were studied at 23 °C and 80 °C by using the second derivative deconvolution method of the IR spectra. Our results demonstrated that the ability of the salts to stabilize/destabilize these two proteins correlates with the Hofmeister series of ions. At the same time, some exceptions were also observed. The destabilization of the native structures of both α-helical albumin and β-structural trypsin upon interaction with neutral salts leads to the formation of intermolecular β-sheets typical for amyloid fibrils or amorphous aggregates. Thus, our quantitative FTIR-spectroscopy analysis allowed us to further clarify the mechanisms and complexity of the neutral salt actions on protein structures which may lead to strategies preventing unwelcome misfolding of proteins.

The effect of Berberine on the secondary structure of human serum albumin

2005 ◽  
Vol 743 (1-3) ◽  
pp. 79-84 ◽  
Author(s):  
Ying Li ◽  
WenYing He ◽  
Jianniao Tian ◽  
Jianghong Tang ◽  
Zhide Hu ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum

Human Serum Albumin Conformational Changes as Induced by Tenoxicam and Modified by Simultaneous Diazepam Binding

1993 ◽  
Vol 45 (12) ◽  
pp. 1050-1053 ◽  
Author(s):  
F. BRÉE ◽  
S. URIEN ◽  
P. NGUYEN ◽  
J. P. TILLEMENT ◽  
A. STEINER ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Conformational Changes

Calcium ion binding to clinically relevant chemical modifications of human serum albumin

1995 ◽  
Vol 41 (11) ◽  
pp. 1654-1661 ◽  
Author(s):  
H Vorum ◽  
K Fisker ◽  
M Otagiri ◽  
A O Pedersen ◽  
U Kragh-Hansen
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Conformational Changes ◽  
Calcium Binding ◽  
Equilibrium Dialysis ◽  
Thiol Group ◽  
Protein Molecule ◽  
Penicillin G ◽  
Lysine Residues

Abstract Calcium binding to glycated, penicilloylated, acetylated, and normal defatted human serum albumin as well as to mercapt- and nonmercaptalbumin was studied by equilibrium dialysis of radioactive Ca2+. Binding was quantified by five Scatchard constants [ni = 1, (i = 1-4) and n5 = 10]. Glycation resulted in increased k1- and k2-values and unchanged k3-k5-values, whereas penicilloylation increased all five association constants. The increments were greater the more pronounced the modification, and the enhancements caused by penicilloylation were, for the same degree of modification, greater than those produced by glycation. In contrast, acetylation by acetylsalicylate did not affect calcium binding. Likewise, binding to mercapt- and nonmercaptalbumin was the same, a finding showing that the thiol group of cysteine 34 is not important for calcium binding. D-Glucose and penicillin G are known to react with lysine residues of albumin, and the enhancement of binding resulting from glycation or penicilloylation is probably brought about by unspecific electrostatic effects, possibly supplemented by conformational changes of the protein molecule. The relative importance of the three domains of human serum albumin for calcium binding is discussed.

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