Hi Sri,
I am going to submit thesis soon. So will take some time to find
specific details about your queries. In the mean time you may try
ammonium sulphate precipitation method. It works out for me all the
time without degrading enzyme activity. If enzyme yield is not
important to you, this will precipitate all the proteins without
denaturation. Latter you may run TLC/ native PAGE to get some amount
of it. For bulk separation, I still doubt you may have to use size
exclusion column chromatography. All techniques I spoke aye affordable
& easy to use.
Happy Diwali & good luck.

Sandeep