Biophysical Society Conference | Tahoe 2022

Molecular Biophysics of Membranes

Thursday Speaker Abstracts

DECIPHERING AN INTERFACIALITY SCALE FOR PROTEINS AT BIOLOGICAL MEMBRANES Ismael Mingarro 1 ; Brayan Grau 1 ; Maria J Garcia-Murria 1 ; Manuel M Sanche del Pino 1 ; Luis Martinez-Gil 1 ; 1 University of Valencia, Biochemistry and Molecular Biology, Valencia, Spain Biological membranes are formed by a hydrophobic core surrounded by two interfacial regions that together are comparable in size to the former. The insertion and folding of most α -helical membrane proteins in this heterogeneous environment require the assistance of protein- conducting channels termed translocons. Accumulated precise functional and structural knowledge about how translocons work helped to understand the insertion of hydrophobic sequences into biological membranes and to develop translocon-based hydrophobicity scales. However, an equivalent analysis of the interfacial propensity of a particular sequence is not yet available. By challenging the ER Sec61 translocon with a large set of designed interfacial polypeptide sequences, we have determined the propensity of all 20 amino acids to achieve a membrane interfacial disposition. These estimated interfacial propensities can be converted to apparent free energies for direct comparison with previous biophysical data.

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