That center brace is there for a reason. While it's "just plastic" is has a lot tensional strength. That is, in the direction of the width of the tank, it has a lot of strength in tension. So with that gone, your glass is bending outward with the force of the water because it's support structure is gone. Glass doesn't have much strength in it's cross section. In short order, you could have a big mess on your hands.
You should definitely drain the tank down a ways to relieve the pressure. Then you should figure out how to either replace or repair the tank. Sometimes LFS have cracked tanks and you might be able to buy a 55g damaged tank, take the top frame off and replace the one on your tank. Or if that's not an option, you could get a piece of plastic and try to repair it with epoxy and mechanical fasteners.
At any rate, the aquarium manufacturers put that center brace in there for a reason. And I think on the All Glass website, they say not to use an aquarium with a broken center brace. If there is a 110g without a center brace, then it was probably designed with thicker glass.