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Peptides at membrane surfaces and their role in prebiotic evolution
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Chipot, Christophe Pohorille, Andrew Wilson, Michael A. |
| Copyright Year | 2002 |
| Description | Protocells had to transport ions and organic matter across membranes separating the interior of the cell from the environment, capture and utilize energy and transduce environmental signals. In a series of detailed, molecular-level computer simulations we show how these peptides in contact with membranes can acquire ordered structures and functions. We have investigated the stability of a simple alpha-helical peptide containing Leucine (L) and Serine (S) of the form (LSLLLSL)3 in a model membrane system. The parallel in-plane state is the most stable configuration. The transmembrane state is metastable, and about 15 kcal/mol is required to insert the peptide into the membrane. We investigated dimes of both (LSLLLSL)3 and glycophorin A, and show how the free energy of helix association can, at least partially, offset the free energy of insertion. We have also investigated the transmembrane pore of the influenza M2 protein. This aggregate of four identical alpha-helices, each built of 25 amino acids, forms an efficient and selective voltage-gated proton channel. Our simulations explain the gating mechanism, which can involve strands of hydrogen-bonded water through the pore or proton transfer through tautomerization of protein residues. The channel can be re-engineered to act as a simple proton pump. |
| File Size | 1924018 |
| Page Count | 36 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20020091929 |
| Archival Resource Key | ark:/13960/t46q6x178 |
| Language | English |
| Publisher Date | 2002-08-23 |
| Access Restriction | Open |
| Subject Keyword | Proteins Protons Membranes Protobiology Peptides Influenza Amino Acids Computerized Simulation Molecular Biology Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
