The amphipaticity concept: a key to understand protein folding from the interaction of a peptide with SDS

ERNESTO A ROMÁN; PABLO ROSI; MARIANO GONZALEZ LEBRERO; RODOLFO WUILLOUD; LUIS GONZÁLEZ FLECHA; JOSÉ MARÍA DELFINO; JAVIER SANTOS

Buzios Brasil

Congreso; VII Iberoamerican Congress of Biophysics; 2009

<!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 159 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:10.0pt; margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:12.0pt; mso-bidi-font-size:11.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} p {mso-style-noshow:yes; mso-style-priority:99; mso-margin-top-alt:auto; margin-right:0cm; mso-margin-bottom-alt:auto; margin-left:0cm; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:12.0pt; mso-ansi-font-size:12.0pt; mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} .MsoPapDefault {mso-style-type:export-only; margin-bottom:10.0pt; line-height:115%;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> A glance at the sequence of a protein does not directly reveal the existence of structure; however, it encrypts the physicochemical properties needed to assemble in a tridimensional array (Anfinsen 1973). Probably, an extremely simple example that illustrates how a sequence determines a structure is the case of an amphipatic α-helix. The amphipaticity of the peptide structure is a property that arises from the coil to helix transition and, in general this very common feature is a consequence of both local (intra helical interactions) and tertiary interactions (with the rest of the protein). In this work, we explore the interaction of SDS with TRX 94-108 peptide by  means of the effect on the structure. We performed far UV circular dichroism experiments, HPLC reverse phase C-18 chromatography, and capillar electrophoresis. Moreover, we characterized the interaction of SDS and the peptide using Molecular Dynamics Simulation.