AA changes value fast

[Dialect]

First session with villain, no reads.

How do I play this turn after my monster has disentigrated into the idiot end of a straight?

Full Tilt Poker, $0.50/$1 NL Hold'em Cash Game, 6 Players
LeggoPoker Hand History Converter

UTG: $40.35
MP: $18.75
Hero (CO): $105
BTN: $117.90
SB: $150.15
BB: $100

Pre-Flop: A[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/heart.gif[/img] dealt to Hero (CO)
UTG calls $1, MP folds, <font color="red">Hero raises to $4.50</font>, BTN calls $4.50, 2 folds, UTG calls $3.50

Flop: ($15) 4[img]/images/graemlins/diamond.gif[/img] 3[img]/images/graemlins/diamond.gif[/img] 5[img]/images/graemlins/club.gif[/img] (3 Players)
UTG checks, <font color="red">Hero bets $12</font>, BTN calls $12, UTG folds

Turn: ($39) 2[img]/images/graemlins/club.gif[/img] (2 Players)
Hero ????