Tertiary structural changes of the alpha-hemolysin from Staphylococcus aureus on association with liposome membranes


Autoria(s): Bortoleto, R. K.; de Oliveira, AHC; Ruller, R.; Arni, R. K.; Ward, R. J.
Contribuinte(s)

Universidade Estadual Paulista (UNESP)

Data(s)

20/05/2014

20/05/2014

01/03/1998

Resumo

The interaction of alpha-hemolysin (also called alpha-toxin) from Staphylococcus aureus with mixed egg-yolk phosphatidylcholine/cholesterol liposomes has been investigated using the intrinsic tryptophan fluorescence emission (ITFE) signal. The ITFE intensity of alpha-hemolysin, which was obtained using a novel purification protocol, showed a triphasic increase on incubation with liposomes at low protein/lipid ratios. The first, rapid phase results in an increase in ITFE of 10%, which reflects rapid conformation changes in the alpha-hemolysin on association with the liposome membrane, the second phase of the ITFE increase is associated with a red shift from 334 to 339 nm in the maximum emission wavelength, suggesting the transition to a partially unfolded intermediate in the oligomerization process. The third phase of the ITFE intensity change demonstrates a temporal correlation with the appearance of SDS-stable oligomers. The results demonstrate the feasibility of identification of intermediate protein conformations in complex membrane-associated processes by manipulation of the liposomal membrane composition. (C) 1998 Academic Press.

Formato

47-52

Identificador

http://dx.doi.org/10.1006/abbi.1997.0550

Archives of Biochemistry and Biophysics. San Diego: Academic Press Inc., v. 351, n. 1, p. 47-52, 1998.

0003-9861

http://hdl.handle.net/11449/21966

10.1006/abbi.1997.0550

WOS:000072310900007

Idioma(s)

eng

Publicador

Academic Press Inc.

Relação

Archives of Biochemistry and Biophysics

Direitos

closedAccess

Palavras-Chave #alpha-hemolysin #alpha-toxin #Staphylococcus aureus #pore-forming #liposome membrane #unfolded intermediate
Tipo

info:eu-repo/semantics/article