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Studies that focus on packing interactions between transmembrane (TM) helices in membrane proteins would greatly benefit from the ability to investigate their association and packing interactions in multi‐spanning TM domains. However, the production, purification, and characterization of such units have been impeded by their high intrinsic hydrophobicity. We describe the polar tagging approach to biophysical analysis of TM segment peptides, where incorporation of polar residues of suitable type and number at one or both peptide N‐ and C‐termini can serve to counterbalance the apolar nature of a native TM segment, and render it aqueous‐soluble. Using the native TM sequences of the human erythrocyte protein glycophorin A (GpA) and bacteriophage M13 major coat protein (MCP), properties of tags such as Lys, His, Asp, sarcosine, and Pro‐Gly are evaluated, and general procedures for tagging a given TM …