Effects of salt and denaturant on structure of the amino terminal alpha-helical segment of an antibacterial peptide dermaseptin and its binding to model membranes.
Indian J Biochem Biophys
;
2001 Jun; 38(3): 142-8
Artigo
em Inglês
| IMSEAR
| ID: sea-28273
ABSTRACT
The amino terminal 1-18 domain of dermaseptin s is an important determinant of its structure as well as the antibacterial activity. A thorough investigation on the structure of the 18-residue peptide (D18) and its binding to model membranes in presence of salt and denaturant guanidinium chloride has been carried out. In presence of salt, there is an increase in the fraction of peptide molecules in helical conformation. In presence of the denaturant, D18 is unordered, but addition of the structure-promoting solvent trifluoroethanol results in a transition to the helical conformation. In presence of denaturant, the peptide is unordered, but binding to lipid vesicles is not abolished. Investigation of model membrane permeabilizing ability of the peptide in solutions containing various proportions of sodium chloride and guanidinium chloride indicates that vesicle permeabilization parallels extent of binding. The peptide thus binds to lipid vesicles in an unfolded state. Since the peptide has propensity to fold into a helical conformation, lipid induced transition to a helical structure occurs, followed by membrane permeabilization as a result of pore formation.
Texto completo:
DisponíveL
Índice:
IMSEAR (Sudeste Asiático)
Assunto principal:
Biossíntese Peptídica
/
Ligação Proteica
/
Conformação Proteica
/
Desnaturação Proteica
/
Sais
/
Espectrofotometria
/
Fatores de Tempo
/
Trifluoretanol
/
Dados de Sequência Molecular
/
Sequência de Aminoácidos
Tipo de estudo:
Estudo prognóstico
Idioma:
Inglês
Revista:
Indian J Biochem Biophys
Ano de publicação:
2001
Tipo de documento:
Artigo
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