Bola amphiphiles monolayer membranes

Boc protecting group, 162-163 (See also Peptides) BOC-ON reagent for Boc-protection, 327 Bola amphiphiles monolayer membranes, 351... 

Munoz, S. Mallen, J. Nakano, A. Chen, Z. Gay, L Echegoyen, L. Gokel, G. W., (1993) Ultrathin monolayer lipid membranes from a new family of crown ether-based bola-amphiphiles J. Am. Chem. Soc. 115, 1705-1711. 

In nature, asymmetry is achieved through membrane dissolved proteins. In lipid membrane systems without proteins, only monolayers made of bola-amphiphiles allow a totally asymmetric arrangement of head groups. The simplest asymmetry to be achieved is dependent on the one-sided precipitation of bolaamphiphiles. a,to-Dicarboxylic acids, for example, are often soluble at pH > 8 and spontaneously form vesicles upon acidification to pH 5. At a lower pH, all carboxyl groups become protonated and one usually observes ill-defined precipitates . 

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