If you think he is a loose caller pf, then make a 600-700 bet here. You got a good draw, and might even have the best hand right now. If you make a bet, you represent AK in his eyes, and if he calls and the 9 comes, you are as good as gold. You could check behind here, but he will be sure to bet the turn 9/10 times. I'd make a good bet on this flop, and if he calls and checks the turn, check behind if you didn't hit. Then if you hit a 9, J, Q, or A, you might have a winner (especially if you hit your straight) and he is very likely to try to steal a pot there.

If he reraises you on the flop, he's got AK, depending on the size of his raise, act accordingly. At least you would know if he did reraise you, a jack or queen isn't helping you out whatsoever.