Related Experiment Video
Updated: Jul 17, 2026
Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids
Published on: March 21, 2025
pH-dependent protein conformational changes in albumin:gold nanoparticle bioconjugates: a spectroscopic study
Li Shang1, Yizhe Wang, Junguang Jiang
1State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Changchun, Jilin 130022, People's Republic of China.
Bovine serum albumin (BSA) undergoes significant structural changes when bound to gold nanoparticles. These conformational changes, affecting both secondary and tertiary structures, are influenced by pH, with greater alterations observed at higher pH levels.
Area of Science:
- Bioconjugation Science
- Protein Chemistry
- Nanomaterial Science
Background:
- Bovine serum albumin (BSA) is a widely used protein in bioconjugation.
- Gold nanoparticles (AuNPs) are increasingly utilized in biomedical applications.
- Understanding protein-nanoparticle interactions is crucial for developing effective bioconjugates.
Purpose of the Study:
- To investigate the conformational changes of BSA upon adsorption onto gold nanoparticles.
- To analyze the impact of pH on BSA structure in bioconjugates.
- To elucidate the secondary and tertiary structural alterations of BSA.
Main Methods:
- Spectroscopic techniques including UV-vis absorption, fluorescence, circular dichroism (CD), and Fourier transform infrared (FTIR) spectroscopy were employed.
- Bioconjugates were prepared using a standard adsorption method.
- Experiments were conducted at varying pH values (3.8, 7.0, and 9.0).
Main Results:
- BSA exhibited substantial conformational changes at both secondary and tertiary structure levels when forming bioconjugates with gold nanoparticles.
- BSA adopted a more flexible conformation at the nanoparticle surface.
- The extent of conformational changes was significantly influenced by pH, with larger alterations observed at higher pH values.
Conclusions:
- The adsorption method leads to significant structural modifications in BSA when forming bioconjugates with gold nanoparticles.
- BSA's conformational flexibility is enhanced on the gold nanoparticle surface.
- pH plays a critical role in modulating BSA's structural response to gold nanoparticle conjugation, with higher pH inducing more pronounced changes.
