I agree with Mark, except that I wouldn't even try sonication, Triton or
freeze/thaw cycles in that case.
I'd look for emulsification (with a Homogenizer) in a cold room, but if you go
quickly and gently with the French Press (either in a cold room or by using a
cold piston) it might help. Don'
try experimenting with different, especially protease-deficient, E coli strains
to express the protein and try different methods to lyse the bacteria
(sonication, french-press, emulsification, bead-beater, mortar & pestle under
liquid nitrogen).
on the other hand, if you are lucky, you are just
