The flop action screams set, but on a draw-less board I don't know why villain would bet the turn so hard. Still, there's no way he doesn't put AK as your most likely hand here, with the possibility of AA. He probably knows there's a small chance he can take you off AK (if you're ahead) and a much smaller chance of taking you off AA; thus, this probably isn't a bluff, and I think you're behind. Fold.