Flopped DBB and FD against uber-aggressive LAG.

[payoff wizard]

Villain is 37/36/4.27, and has displayed an unwillingness to be taken off hands pre-flop, often floating with air.

***** Hand History for Game 5735619943 *****
$25 NL Texas Hold'em - Monday, March 05, 01:11:59 ET 2007
Table Table 131354 (Real Money)
Seat 6 is the button
Total number of players : 6
Seat 5: MCDoubleV ( $47.17 )
Seat 1: HERO ( $33.99 )
Seat 3: PropositionMike ( $81.73 )
Seat 6: sikchild ( $14.40 )
Seat 2: wilkel111 ( $32.73 )
Seat 4: njcnm ( $23.05 )
HERO posts small blind [$0.10].
wilkel111 posts big blind [$0.25].
** Dealing down cards **
Dealt to HERO [ 5s 4s ]
PropositionMike raises [$1.25]
njcnm folds.
MCDoubleV folds.
sikchild folds.
HERO calls [$1.15]
wilkel111 folds.
** Dealing Flop ** [ 3c, As, 7s ]
HERO checks.
PropositionMike bets [$1.90]
HERO raises [$4.71]
PropositionMike calls [$2.81]
** Dealing Turn ** [ 8d ]
HERO bets [$12.75]
PropositionMike raises [$49.80]
HERO?????

Given that even most air beats me unless I hit my river, am I committed to call villain's raise on the turn? Any comments welcome.