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Updated: Jun 13, 2026

Sedimentation Equilibrium of a Small Oligomer-forming Membrane Protein: Effect of Histidine Protonation on Pentameric Stability
Published on: April 2, 2015
Concentration and pH-dependent aggregation behavior of an l-histidine based amphiphile in aqueous solution
Arjun Ghosh1, Saurabh Shrivastava, Joykrishna Dey
1Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India.
Abstract:
The surface activity and self-assembly behavior of zwitterionic amphiphile N-(2-hydroxydodecyl)-l-histidine (C(12)HHis) were studied in phosphate buffers of pH 2 and 13 using surface tension and fluorescence probe techniques, respectively. Transmission electron microscopic images of the aggregates have revealed existence of nano-size vesicles in dilute solutions of both acidic and basic pH. In basic medium, the vesicles are converted to tubular aggregates upon increase of surfactant concentration. The nanotubes undergo phase transition to form elongated or small rod-like micelles at a much higher concentration of the amphiphile. The vesicles and nanotubes were found to become more stable upon addition of 10mol% of cholesterol.
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