stupid newb - can't add material to imported obj

sorry for the dumb question.

I have imported an obj of a protein that came from Chimera and the Protein Data Base.

But the obj will not accept any material. The sphere in the materials tab is updated but the mesh isn’t. I keep a cube in the scene and that is updated fine.

I have tried flipping the normals.

The obj is 1.5M and the blend is 4.1M.

Thanks for any advice.

2.49, xp

OK I think this might be a Chimera thing.

If I export the protein mesh from chimera as a vrml I can texture it. If I export it as a obj I cannot texture it.