Impact of multiple quaternary ammonium salts on dynamic properties of BSA adsorption layer at different pH values
| Autor: | Zhao-Hua Ren, Yi Liu, Qi-Xiang Mei, Lu Lai, Zhi-Qiang Zhou, Ping Mei, Yan-Cheng Zheng |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Circular dichroism
Quenching (fluorescence) biology Chemistry 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences chemistry.chemical_compound Adsorption Isoelectric point Chemical engineering biology.protein Organic chemistry Molecule Ammonium Bovine serum albumin 0210 nano-technology Protein secondary structure |
| Zdroj: | Soft Matter. 13:7273-7282 |
| ISSN: | 1744-6848 1744-683X |
| DOI: | 10.1039/c7sm01607g |
| Popis: | The interaction mechanism of multiple quaternary ammonium salts (MQAS) with bovine serum albumin (BSA) was examined by the fluorescence quenching method and circular dichroism (CD) spectra. Moreover, the effects of MQAS on the dynamic properties of BSA adsorption layers at different pH values were investigated using dilational interfacial rheology. Results show that the quenching constants increase with an increase in pH values and decrease with an increase in the experiment temperature at pH 5.3. The quenching mechanism is static quenching, and the electrostatic force dominates the interaction between MQAS and BSA at pH 5.3. Due to three positive head groups, MQAS can significantly affect the dynamic interfacial activity of BSA molecules at a relatively low concentration. At pH 4.3, the electrostatic repulsion is unfavorable for the formation of MQAS/BSA complexes. Consequently, MQAS molecules will replace BSA molecules from the interface by competitive adsorption. At the pH value above the isoelectric point of BSA, the electrostatic attraction is better for the formation of MQAS/BSA complexes, which exhibit a rapid adsorption rate and an enhanced interfacial activity. Moreover, the kinetic dependencies of interfacial dilational elasticity for the MQAS/BSA mixtures become nonmonotonous. The appearance of the maximum interfacial elasticity values can be attributed to the formation of tails and loops, which suggests that the addition of MQAS destroys the secondary and tertiary structure of protein in the bulk phase. In addition, the effects of MQAS on the secondary structure of protein were demonstrated by CD spectra. |
| Databáze: | OpenAIRE |
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