Polar side chains drive the association of model transmembrane peptides.

ABSTRACT: The forces stabilizing the three-dimensional structures of membrane proteins are currently not well understood. Previously, it was shown that a single Asn side chain in a transmembrane segment can mediate the dimerization and trimerization of a variety of hydrophobic helices. Here, we examine the tendencies of a representative set of amino acids (Asn, Gln, Asp, Glu, Lys, Ala, Val, Leu, Ser, Thr) to direct the oligomerization of a model transmembrane helix. The model peptide is entirely hydrophobic throughout a 20-residue segment and contains a single central site for the introduction of various amino acid "guests." Analytical ultracentrifugation and gel electrophoresis were used to determine the stoichiometry and free energy of association of the entire set of peptides within micelles. Var

SUBMITTER: Gratkowski H 

PROVIDER: S-EPMC14678 | biostudies-literature | 2001 Jan

REPOSITORIES: biostudies-literature