Fibrillogenesis of human serum albumin in the presence of levodopa – spectroscopic, calorimetric and microscopic studies

Ajmal, Mohammad; Chandel, Tajalli Ilm; Alam, Parvez; Zaidi, Nida; Zaman, Masihuz; Nusrat, Saima; Khan, Mohsin Vahid; Siddiqi, Mohammad Khursheed; Shahein, Yasser E.; Mahmoud, Mohamed H.; Badr, Gamal

doi:10.1016/j.ijbiomac.2016.10.025

Cited by 39 publications

(8 citation statements)

References 51 publications

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“…On the other hand it must be considered that BSA is a globular type protein so we believe non structured aggregation instead of fibrillation may be the most plausible mechanism to explain results of Fig 2 . However it has been reported that BSA [ 33 ] and lysozyme [ 34 ] can generate fibrillar structures in a few hours after thermal shock, this aggregation mechanism were evidenced by using electron microscopy (TEM), and atomic force microscopy (AFM) techniques to access and characterize the whole aggregation pathway.…”

Section: Resultsmentioning

confidence: 99%

Study of conformational changes and protein aggregation of bovine serum albumin in presence of Sb(III) and Sb(V)

et al. 2017

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Antimony is a metalloid that affects biological functions in humans due to a mechanism still not understood. There is no doubt that the toxicity and physicochemical properties of Sb are strongly related with its chemical state. In this paper, the interaction between Sb(III) and Sb(V) with bovine serum albumin (BSA) was investigated in vitro by fluorescence spectroscopy, and circular dichroism (CD) under simulated physiological conditions. Moreover, the coupling of the separation technique, asymmetric flow field-flow fractionation, with elemental mass spectrometry to understand the interaction of Sb(V) and Sb(III) with the BSA was also used. Our results showed a different behaviour of Sb(III) vs. Sb(V) regarding their effects on the interaction with the BSA. The effects in terms of protein aggregates and conformational changes were higher in the presence of Sb(III) compared to Sb(V) which may explain the differences in toxicity between both Sb species in vivo. Obtained results demonstrated the protective effect of GSH that modifies the degree of interaction between the Sb species with BSA. Interestingly, in our experiments it was possible to detect an interaction between BSA and Sb species, which may be related with the presence of labile complex between the Sb and a protein for the first time.

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Section: Resultsmentioning

confidence: 99%

Study of conformational changes and protein aggregation of bovine serum albumin in presence of Sb(III) and Sb(V)

et al. 2017

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“…76 In our case, the binding affinity between heparin and BSA protein is very much apparent with an appreciable heat of interaction or a specific heat pattern. The enthalpy change is largely negative with an overall exothermicity of ∼ ΔH = −262.24 × 10 3 cal mol −1 , and the change in Gibbs free energy (ΔG) is also negative, which indicates that the reaction is spontaneous in nature and ΔH and ΔS are largely negative, representing that binding is of heparin with BSA and is driven by hydrogen bonding interactions, 78 as shown in Table 5. This exothermic nature can be directly associated with aggregation of BSA induced by heparin as there are already reports which suggest that aggregation of protein is a exothermic in nature.…”

Section: Discussionmentioning

confidence: 99%

Heparin Accelerates the Protein Aggregation via the Downhill Polymerization Mechanism: Multi-Spectroscopic Studies to Delineate the Implications on Proteinopathies

et al. 2021

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Heparin is one of the members of the glycosaminoglycan (GAG) family, which has been associated with protein aggregation diseases including Alzheimer’s disease, Parkinson’s disease, and prion diseases. Here, we investigate heparin-induced aggregation of bovine serum albumin (BSA) using different spectroscopic techniques [absorption, 8-anilino-1-naphthalene sulfonic acid (ANS) and thioflavin T (ThT) fluorescence binding, and far- and near-UV circular dichroism]. Kinetic measurements revealed that heparin is involved in the significant enhancement of aggregation of BSA. The outcomes showed dearth of the lag phase and a considerable change in rate constant, which provides conclusive evidence, that is, heparin-induced BSA aggregation involves the pathway of the downhill polymerization mechanism. Heparin also causes enhancement of fluorescence intensity of BSA significantly. Moreover, heparin was observed to form amyloids and amorphous aggregates of BSA which were confirmed by ThT and ANS fluorescence, respectively. Circular dichroism measurements exhibit a considerable change in the secondary and tertiary structure of the protein due to heparin. In addition, binding studies of heparin with BSA to know the cause of aggregation, isothermal titration calorimetry measurements were exploited, from which heparin was observed to promote the aggregation of BSA by virtue of electrostatic interactions between positively charged amino acid residues of protein and negatively charged groups of GAG. The nature of binding of heparin with BSA is very much apparent with an appreciable heat of interaction and is largely exothermic in nature. Moreover, the Gibbs free energy change (ΔG) is negative, which indicates spontaneous nature of binding, and the enthalpy change (ΔH) and entropy change (ΔS) are also largely negative, which suggest that the interaction is driven by hydrogen bonding.

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“…HSA, the most abundant protein in blood plasma, contributes significantly to control and regulate the osmotic pressure and various metabolic processes and also acts as a multifunctional transport protein in the circulatory system. , HSA, a natively α-helical (>60%) protein, comprises a single polypeptide chain of 585 amino acid residues organized in three homologous domains . Earlier studies have shown that the formation of amyloid fibrils by destabilization of the native structure of HSA is achievable by controlling specific solution conditions like pH, ionic strength, temperature etc. − Additionally, various external factors like metal ions, sugars, surfactants and other organic molecules have been reported to affect the fibrillation of HSA differently. − …”

Section: Introductionmentioning

confidence: 99%

Does Surface Chirality of Gold Nanoparticles Affect Fibrillation of HSA?

2017

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In order to demonstrate the influence of the surface chirality of the nanoparticles on amyloid fibrillation, the inhibiting effectiveness of the chiral gold nanoparticles, synthesized using the two enantiomeric forms (i.e., d- and l-) of glutamic acid, toward the fibrillation of human serum albumin (HSA) has been investigated. Here the enantiomers of glutamic acid are used as both reducing and stabilizing/capping agents. It is found that the surface chirality is the only major difference between the d-glutamic acid mediated gold (DGAu) and l-glutamic acid mediated gold (LGAu) nanoparticles. The fibrillation process has been monitored using various biophysical techniques, e.g., turbidity assay, Thioflavin T fluorescence kinetics, Congo red binding study, circular dichroism spectroscopy, fluorescence microscopy, and transmission electron microscopy. The experimental results illustrate that DGAu is more effective in inhibiting the formation of HSA fibrils than LGAu. Furthermore, the differential inhibiting effect of DGAu and LGAu toward HSA fibrillation has been described on the basis of the dissimilar interaction behavior of the nanoparticles with the HSA molecules, as revealed by the Trp fluorescence quenching, and the isothermal titration calorimetry. It is suggested that the surface chirality of the gold nanoparticles strongly influences the protein adsorption dynamics including the modes of orientation of adsorbed HSA molecules, causing the inhibition of fibrillation to different extents.

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Fibrillogenesis of human serum albumin in the presence of levodopa – spectroscopic, calorimetric and microscopic studies

Cited by 39 publications

References 51 publications

Study of conformational changes and protein aggregation of bovine serum albumin in presence of Sb(III) and Sb(V)

Study of conformational changes and protein aggregation of bovine serum albumin in presence of Sb(III) and Sb(V)

Heparin Accelerates the Protein Aggregation via the Downhill Polymerization Mechanism: Multi-Spectroscopic Studies to Delineate the Implications on Proteinopathies

Does Surface Chirality of Gold Nanoparticles Affect Fibrillation of HSA?

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