EurekaMag.com logo
+ Site Statistics
References:
52,725,316
Abstracts:
28,411,598
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Raman ir spectroscopic study of gramicidin a conformations


Archives of Biochemistry & Biophysics 202(2): 639-649
Raman ir spectroscopic study of gramicidin a conformations
Raman scattering and IR spectroscopic techniques were used to study the vibrational spectrum and conformation of the membrane channel protein gramicidin A in the solid state, in organic solutions and, using Raman scattering only, in a phospholipid environment. The investigation includes measurements on head- and tail-group modified gramicidin A and a potassium thiocyanate-gramicidin A complex. Tentative identification of the molecular vibrations is proposed on the basis of the data on model compounds. The existence of 4 distinct conformations of the gramicidin A chain is established: conformation I present in the solid state, and CH3OH and CD3OD solutions; conformation II present in films cast from CHCl3 solution; conformation III present in (CH3)2SO and (CD3)2SO solutions at concentrations below 0.5 M gramicidin A; and conformation IV present in the potassium thiocyanate-gramicidin A complex. The data obtainable on a gramicidin A-phospholipid suspension indicate a gramicidin A conformation in this environment corresponding either to the conformation I or II. The details of the spectra in the amide I region are consistent with a .beta.-parallel H-bonded .pi.LD helix for conformational I, in terms of the polypeptide vibrational calculations of Nevskaya and co-workers. Conformation II is consistent with an antiparallel double-stranded .pi.LD helix, while conformations III and IV probably have .pi.-helical structures with larger channel diameters. The data on head- and tail-modified gramicidin A molecules indicate that their confrmations are only slightly different from that of gramicidin A in conformation I.


Accession: 006255772



Related references

Raman and infrared spectroscopic study of gramicidin A conformations. Archives of Biochemistry and Biophysics 202(2): 639-649, 1980

Raman spectroscopic investigation of gramicidin A' conformations. Science 185(4151): 616-618, 1974

Raman spectroscopic investigation of gramicidin a prime conformations. Science (Washington D C) 185(4151): 616-618, 1974

A raman spectroscopic study on conformations of DNA oligomers: A dominant effect of an AA:TT sequence over those of AT:AT and TA:TA sequences on determining conformations of DNA duplexes. Nucleosides and Nucleotides 13(6-7): 1467-1481, 1994

A Raman spectroscopic study on the sequence dependent conformations of DNA oligomers. Nucleic Acids Symposium Series: 195-198, 1986

Solvent history dependence of gramicidin-lipid interactions: a Raman and infrared spectroscopic study. Biophysical Journal 65(6): 2484-2492, 1993

Solvent history dependence of gramicidin-lipid interactions A Raman and FTIR spectroscopic study. Biophysical Journal 64(2 PART 2): A61, 1993

A Raman spectroscopic study on the interaction of an ion-channel protein with a phospholipid in a model membrane system (gramicidin A/L-alpha-lysophosphatidylcholine). European Journal of Biochemistry 160(2): 395-400, 1986

Effect of the gt wobble base pair on z dna and b dna conformations a raman spectroscopic study of the self complementary dna hexamer d cgcgtg. Biophysical Journal 51(2 PART 2): 504A, 1987

Environments and conformations of tryptophan side chains of gramicidin A in phospholipid bilayers studied by Raman spectroscopy. Biochemistry 29(6): 1572-1579, 1990