Anion-specific binding to n-hexadecyl phosphorylcholine micelles
Jacks P Priebe1, Bruno S Souza, Gustavo A Micke
1Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis-SC 88040-900, Brazil.
Langmuir : the ACS Journal of Surfaces and Colloids
|August 29, 2009
Summary
Hexadecyl phosphorylcholine (HPC) micelles incorporate anions, creating a negative charge. Added salts enhance this negative charge, affecting micelle behavior and reactions, relevant to biological amphiphiles.
Area of Science:
- Colloid and Surface Chemistry
- Physical Chemistry
- Biophysical Chemistry
Background:
- Hexadecyl phosphorylcholine (HPC) is a zwitterionic amphiphile forming micelles.
- Understanding micelle interfacial properties is crucial for biological amphiphile behavior.
Purpose of the Study:
- To investigate the charge distribution and behavior of hexadecyl phosphorylcholine (HPC) micelles.
- To elucidate the influence of anions and salts on HPC micelle properties and reactivity.
Main Methods:
- Zeta potential measurements to determine micellar charge.
- Kinetic studies of hydrolysis and reaction rates in HPC micelles.
- Analysis of salt effects (NaCl, NaClO4) on micellar properties.
Main Results:
- HPC micelles exhibit an anionoid character with a negative zeta potential.
- Hydronium ion incorporation increases micellar negative charge.
- Salts increase the rate of A1 hydrolysis and inhibit OH- reactions, with NaClO4 having a larger effect than NaCl.
- Increased negative charge leads to greater headgroup repulsion and reduced aggregation number.
Conclusions:
- HPC micelles possess a net negative charge due to anion incorporation.
- Salt concentration significantly modulates HPC micelle charge, aggregation, and reactivity.
- These findings provide insights into the behavior of biological phosphorylcholine amphiphiles.
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