Studies on Triton X-100 detergent micelles

Area of Science:

• Surfactant chemistry
• Physical chemistry
• Biophysical chemistry

Background:

• Triton X-100 (TX-100) is a non-ionic surfactant widely used in biological and chemical applications.
• Understanding micelle formation is crucial for its effective utilization in various processes.

Purpose of the Study:

• To determine the micelle number and aggregation behavior of Triton X-100 at 25°C.
• To investigate the binding characteristics of 1-anilino-8-naphthalene sulfonate (ANS) to TX-100 micelles.

Main Methods:

• Sedimentation equilibrium ultracentrifugation to determine apparent molecular weight and micelle number.
• Fluorescence spectroscopy, including fluorescence titration with ANS, to study micelle formation and ligand binding.

Main Results:

• The apparent molecular weight of the major Triton X-100 micelle was determined to be 81,250, corresponding to a micelle number of 125.
• Fluorescence titration revealed a micelle number of 121 and an apparent association constant of 0.9 x 10(5) M for ANS binding.
• Evidence for another TX-100 binding species of variable size was observed.

Conclusions:

• Triton X-100 forms well-defined micelles with a consistent aggregation number at 25°C.
• The binding of ANS to TX-100 micelles is characterized by a moderate association constant.
• The presence of additional TX-100 binding species warrants further investigation.