You say you hydrolyze your samples? Are you digesting them with a non-specific proteinase, or strong acid or base?

Then you should not be surprised to see this kind of smear, as you produce peptides of all sizes.

Achim Recktenwald I am doing it all with different types of proteases i.e. Trypsin, Bromelain, Papain, Alkaline protease, Chymotrypsin.

If you digest your protein with a mix of proteinases, then having such a smear is normal. You produce hundreds if not thousands of different protein fragments and peptides of different size. A gel cannot resolve these into bands.

Try digestion with only 1 proteinase at a time. This would give you the best chance of seeing bands.

If you need to run your sample with all of the proteinases, do it serially, one proteinase after the other, and take samples for your gel between digestions. This allows you yo see the progress in digestion.

Alternatively, find a method to stop the digestion at a specific point in time to have control over the level of digestion you want to achieve.