C. Tokarski, M. Fillet, C. Rolando
Anal. Biochem. 410 98-109 (2011). DOI

Travail réalisé sur le site de l’Université de Lille 1, Sciences et Technologies.

Abstract

We propose an improved acrylamide gel for the sepn. of hydrophobic proteins. The sepn. strategy is based on the incorporation of N-alkylated and N,N’-dialkylated acrylamide monomers in the gel compn. in order to increase hydrophobic interactions between the gel matrix and the membrane proteins. Focusing on the most efficient monomer, N,N’-dimethylacrylamide, the potentiality of the new matrix was evaluated on membrane proteins of the human colon HCT-116 cell line. Protein anal. was performed using an adapted anal. strategy based on FT-ICR tandem mass spectrometry. As a result of this comparative study, including advanced reproducibility expts., more hydrophobic proteins were identified in the new gel (av. GRAVY : -0.085) than in the classical gel (av. GRAVY : -0.411). Highly hydrophobic peptides were identified reaching a GRAVY value up to 1.450, therefore indicating their probable locations in the membrane. Focusing on predicted transmembrane domains, it can be pointed out that 27 proteins were identified in the hydrophobic gel contg. up to 11 transmembrane domains ; in the classical gel, only 5 proteins contg. 1 transmembrane domain were successfully identified. For example, multiple ionic channels and receptors were characterized in the hydrophobic gel such as the sodium/potassium channel and the glutamate or the transferrin receptors whereas they are traditionally detected using specific enrichment techniques such as immunopptn. In total, membrane proteins identified in the classical gel are well documented in the literature, while most of the membrane proteins only identified on the hydrophobic gel have rarely or never been described using a proteomic-based approach