Closed state of gramicidin channel detected by X-ray in-plane scattering
An analogue of gramicidin A (gA) was synthesized with the formyl group replaced by a BOC group. The analogue (BOC-gA) exhibited single channel conduction, but the channel is 5-order-of-magnitude destabilized relative to the gA channel. Hydrated mixtures of gramicidin and dilauroyl phosphatidylcholin...
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Published in | Biophysical chemistry Vol. 49; no. 1; pp. 83 - 89 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Netherlands
Elsevier B.V
01.02.1994
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Subjects | |
Online Access | Get full text |
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Summary: | An analogue of gramicidin A (gA) was synthesized with the formyl group replaced by a BOC group. The analogue (BOC-gA) exhibited single channel conduction, but the channel is 5-order-of-magnitude destabilized relative to the gA channel. Hydrated mixtures of gramicidin and dilauroyl phosphatidylcholine in the molar ratio of 1:10 were prepared into uniformly aligned multiple bilayers, and X-ray scattering with the momentum transfer in the plane of the membrane was measured. Analysis with the help of computer simulations showed that 70% of BOC-gA are monomers. Thus for the first time it was shown that gramicidin monomers are stable inside the monolayers of a lipid membrane. Furthermore, the monomers have the same β helical conformation as the dimeric channel. The result suggests the possibility that when a gramicidin channel is closed, it dissociates into two monomers floating in opposite monolayers. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0301-4622 1873-4200 |
DOI: | 10.1016/0301-4622(93)E0085-J |