1. Conformation of gramicidin-A in CTAB micellar media
- Author
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Nagasuma Chandra, Ashok Kumar Mishra, and J. Shobini
- Subjects
Models, Molecular ,Circular dichroism ,Protein Conformation ,Stereochemistry ,gramicidin A ,Biophysics ,Micelle ,drug conformation ,Fluorescence spectroscopy ,chemistry.chemical_compound ,Pulmonary surfactant ,Bromide ,cationic surfactant ,micelle ,Side chain ,Gramicidin A ,controlled study ,Radiology, Nuclear Medicine and imaging ,Micelles ,Radiation ,Radiological and Ultrasound Technology ,Cetrimonium ,Circular Dichroism ,Gramicidin ,technology, industry, and agriculture ,Cationic polymerization ,cetrimide ,fluorescence spectroscopy ,biological model ,structure analysis ,Crystallography ,Spectrometry, Fluorescence ,priority journal ,chemistry ,Cetrimonium Compounds ,tryptophan derivative ,lipids (amino acids, peptides, and proteins) - Abstract
Gramicidin A (gA) is a linear pentadecapeptide, which exhibits various conformations depending on the environment. The conformational behavior of gA in spherical and rod-shaped cationic micelles formed by cetyltrimethylammonium bromide (CTAB) surfactant has been studied using circular dichroism (CD) and fluorescence spectroscopy, and a probable structure of gramicidin A in CTAB media has been proposed. A CD study shows that gramicidin A assumes ?6.3 helical structure in cationic spherical as well as rod-shaped CTAB micellar media. Modeling studies show the flexibility of the side chain conformation particularly in tryptophan-9. Study of intrinsic fluorescence of tryptophans in gramicidin A indicates three distinct environments for the four-tryptophan residues in CTAB media. ? 2003 Elsevier B.V. All rights reserved.
- Published
- 2003
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