Molecular mechanisms of sweet taste 7: The sweet protein, Thaumatin I

A computer modelling study of the host-guest relationship between the intensely sweet protein named Thaumatin I and our suggested receptor model, an alpha-helical protein, has revealed a perfect fit within a cleft of the Thaumatin I conformation. The parameters and stereoselective interactions for the initiation of the sweetness sensation are interpreted in accord with our previous stereo-interactive studies on a wide range of low molecular weight sweeteners. Also, the Thaumatin data parallels that of the macromolecular sweet protein Monellin, and their intense sweetness arises from the multiple interactions arising within the docking cleft of the protein receptor. The AH(s)/B-s pair of Thaumatin I has been assigned to Lys-97/Asp-98. (C) 1997 Elsevier Science Ltd.