Fig. 4

Hydrophobicity plot of Grin1 in H. sapiens and Aplysia. Kite/Doolittle scale was used to determine the hydrophobicity of each amino acid for the last 450 amino acids, containing the ligand binding domain, TMD, and intracellular C-terminal domain. Despite large evolutionary distance between Aplysia and H. sapiens, only substitutions with similar hydrophobicity are tolerated in TMDs to maintain proper folding of the ion channel. Predicted NMDA and glycine binding sites show many more substitutions that result in changes in hydrophobicity