Phytosterols disaggregate bovine serum albumin under the glycation conditions through interacting with its glycation sites and altering its secondary structure elements

2020 ◽  
Vol 101 ◽  
pp. 104047
Author(s):  
Remah Sobhy ◽  
Ibrahim Khalifa ◽  
Hongshan Liang ◽  
Bin Li
Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2603
Author(s):  
Andra Mihaela Onaș ◽  
Iuliana Elena Bîru ◽  
Sorina Alexandra Gârea ◽  
Horia Iovu

This study investigates the formation of a graphene oxide-polyamidoamine dendrimer complex (GO-PAMAM) and its association and interaction with bovine serum albumin (BSA). Fourier-transform infrared spectrometry and X-ray photoelectron spectrometry indicated the formation of covalent linkage between the GO surface and PAMAM with 7.22% nitrogen content in the GO-PAMAM sample, and various interactions between BSA and GO-PAMAM, including π-π* interactions at 291.5 eV for the binding energy value. Thermogravimetric analysis highlighted the increasing thermal stability throughout the modification process, from 151 to 192 °C for the 10% weight loss temperature. Raman spectrometry and X-ray diffraction analysis were used in order to examine the complexes’ assembly, showing a prominent (0 0 2) lattice in GO-PAMAM. Dynamic light scattering tests proved the formation of stable graphenic and graphenic-protein aggregates. The secondary structure rearrangement of BSA after interaction with GO-PAMAM was investigated using circular dichroism spectroscopy. We have observed a shift from 10.9% β-sheet composition in native BSA to 64.9% β-sheet composition after the interaction with GO-PAMAM. This interaction promoted the rearrangement of the protein backbone, leading to strongly twisted β-sheet secondary structure architecture.


Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1022 ◽  
Author(s):  
Jing Yu ◽  
Yun Chen ◽  
Liqun Xiong ◽  
Xiaoyue Zhang ◽  
Yue Zheng

Proteins, due to their binding selectivity, are promising candidates for fabricating nanoscale bio-sensors. However, the influence of structural change on protein conductance caused by specific protein-ligand interactions and disease-induced degeneration still remains unknown. Here, we excavated the relationship between circular dichroism (CD) spectroscopy and conductive atomic force microscopy (CAFM) to reveal the effect of the protein secondary structures changes on conductance. The secondary structure of bovine serum albumin (BSA) was altered by the binding of drugs, like amoxicillin (Amox), cephalexin (Cefa), and azithromycin (Azit). The CD spectroscopy shows that the α-helical and β-sheet content of BSA, which varied according to the molar ratio between the drug and BSA, changed by up to 6%. The conductance of BSA monolayers in varying drug concentrations was further characterized via CAFM. We found that BSA conductance has a monotonic relation with α-helical content. Moreover, BSA conductance seems to be in connection with the binding ability of drugs and proteins. This work elucidates that protein conductance variations caused by secondary structure transitions are triggered by drug-binding and indicate that electrical methods are of potential application in protein secondary structure analysis.


2017 ◽  
Vol 19 (28) ◽  
pp. 18471-18480 ◽  
Author(s):  
Aristeidis Papagiannopoulos ◽  
Eleni Vlassi ◽  
Stergios Pispas ◽  
Charl J. Jafta

Interactions of BSA with cationic QIm-PCMS aggregates lead to complexes with increased mass, while the BSA secondary structure is critically compromised.


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