MOLECULAR MECHANISMS OF SWEET TASTE-1 - SWEET AND NON-SWEET TASTING AMINO-ACIDS

A novel mechanism is proposed for the AH/B interaction of sweet molecules, such as D-alpha-amino acids with the L-asparagine unit at the N-terminus of a receptor protein which has a right-handed alpha-helical conformation. The lipophilic, dispersive bonding occurs between the side chain of the fifth amino acid residue, from the N-terminus, and either the side chain of the alpha-amino acid or its methine group at the carbon 2. The sequence of AH, B and X groups on the sweet amino acids occurs in a clockwise orientation, when viewed from the receptor.