can Protamine sulfate inhibit or degrage a protein? - (Jun/27/2012 )

hi, i finally manage to express my beta glucosidase gene in e coli rosettagami2 plys s. during lysis, i lysed the pellet, and i gpt some sample from this my crude extract. then i add some protamine sufate and i centrifuge to got the second sample ant use the pellet for the third sample. when i performed western blot, i see my band at 55 kDa although bioinformatic analysis say it is 63kDa. but among the three samples, i saw only a band and it is the one before protamine sulfate . now i wonder about if i inhibit the protein or the band was incorrect? please helpppppp!!!!!!!!!!!!!!!!

molecular weight determination with sds-page is not always (often?) accurate (for various reasons).

and you may not be taking post translational modifications into account.