[gmx-users] big membrane

[Michael]

Dear Gmx-users,
I am a new gmx user so sorry in advance if it is a too simple question
I want to put a protein of 5.4 nm diameter in a dmpc bilayer.
The problem is that i don't know where to get such a big bilayer.
The biggest bilayer I've got is with a box of 6.176 6.176 6.608 and
when i try to put the protein in the membrane it destroys the membrane.
Does anyone know where i can get a dmpc bilayer large enough to put the
protein in it ?
If not,maybey has anyone an idea how to make the membrane bigger?

Thanks in Advance,
Michael Gang.