Volume 23, Issue 24 e202200371
Research Article

pH-Responsive Self-Assembled Compartments as Tuneable Model Protocellular Membrane Systems**

Susovan Sarkar

Corresponding Author

Susovan Sarkar

Department of Biology, Indian Institute of Science Education and Research, Pune, 411008 India

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Shikha Dagar

Shikha Dagar

Department of Biology, Indian Institute of Science Education and Research, Pune, 411008 India

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Kushan Lahiri

Kushan Lahiri

Department of Biology, Indian Institute of Science Education and Research, Pune, 411008 India

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Sudha Rajamani

Corresponding Author

Sudha Rajamani

Department of Biology, Indian Institute of Science Education and Research, Pune, 411008 India

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First published: 15 August 2022
**

A previous version of this manuscript has been deposited on a preprint server (https://doi.org/10.1101/2022.05.14.491926).

Graphical Abstract

The self-assembly behaviour and membrane physicochemical properties of mono-N-dodecyl phosphate (DDP) were studied under different conditions. DDP formed vesicles in low concentration, over a wide range of pH. Physicochemical properties of DDP based membranes changed as a function of pH. Its tuneable nature and unique membrane properties, make it a very enticing model protocell membrane candidate.

Abstract

Prebiotically plausible single-chain amphiphiles are enticing as model protocellular compartments to study the emergence of cellular life, owing to their self-assembling properties. Here, we investigated the self-assembly behaviour of mono-N-dodecyl phosphate (DDP) and mixed systems of DDP with 1-dodecanol (DDOH) at varying pH conditions. Membranes composed of DDP showed pH-responsive vesicle formation in a wide range of pH with a low critical bilayer concentration (CBC). Further, the addition of DDOH to DDP membrane system enhanced vesicle formation and stability in alkaline pH regimes. We also compared the high-temperature behaviour of DDP and DDP:DDOH membranes with conventional fatty acid membranes. Both, DDP and DDP:DDOH mixed membranes possess packing that is similar to decanoic acid membrane. However, the micropolarity of these systems is similar to phospholipid membranes. Finally, the pH-dependent modulation of different phospholipid membranes doped with DDP was also demonstrated to engineer tuneable membranes with potential translational implications.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.