Centrifugation question?

Say you have a density gradient of sucrose in a tube from 1.2 - 1.8g/mL. The sample you want to flow through the gradient contains proteins having a density of 1.37g/mL. No matter how long or how hard you centrifuge them, as long as you don't change their inherent structure (compact them-which would in turn increase their density), could they ever reach the bottom of the tube?