分类: 物理学 >> 核物理学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Strategies for labeling proteins with fluorophores are always important for biotechnology. Here we take a model protein (bovine serum albumin) and a typical fluorophore (rhodamine B) to demonstrate a direct labeling method just by physical adsorption. In combination with size exclusion chromatography and the Scartchard equation, we have developed a facile analysis method for calculating the binding constant and binding sites. The molecular docking method has been used to study the binding site in amino acid level.
分类: 物理学 >> 核物理学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Fluorescence spectroscopy was employed to investigate the interaction between fluorophore fluoresceinamine (FA) and bovine serum albumin (BSA) under physiological conditions. In the mechanism discussion, it was proved that the fluorescence quenching of BSA by FA is a result of the formation of a BSA-FA complex. Fluorescence quenching constants were determined using the modified Stern-Volmer equation to provide a measure of the binding affinity between FA and BSA. The results of the thermodynamic parameters G, H, and S at different temperatures indicated that several kinds of interactions, except for the electrostatic interactions play cooperative roles in BSA-FA association. Furthermore, the conformation of BSA upon interaction with FA was also studied by synchrotron fluorescence spectroscopy.
分类: 物理学 >> 核物理学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Peptide GAV-9 is derived from 3 different disease related proteins. The self-assembly of GAV-9 in a water nanofilm attracted much attention recently. We studied how the temperature factor influenced the peptide self-assembly in a water nanofilm and found interesting phenomena: 1) the higher the temperature, the faster the nanofilaments grow; 2) the GAV-9 peptide formed double monolayers in a water nanofilm at 60 ℃, which further supports the hypothesis that the water nanofilm could change the hydrophobicity of mica. We believe these results can help not only the microcontact printing of amyloid peptides, but also a better understanding on how temperature controls the properties of water nanofilm.
分类: 物理学 >> 核物理学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: Bio-nanosensors (Bio-NSs) have attracted much attention recently due to their unique properties. Among all of the bio-NSs, the intracellular proton sensor is significant for biomedicine studies and clinic diagnosis. Proton nanosensors (PNSs) with different pH sensitive ranges could satisfy different research requirements. Here we report a facile method to build a PNS with a neutral to basic pH sensitive range, in which the commercial pH indicator, fluoresceinamine (FA), was covalently coupled to the carboxylic-rich amphiphilic polymer (AP) coated gold nanoparticles (AuNPs).