every protein is different. Unless your protein has been crystallized earlier, there are no generalized conditions. You have to go the classical way for screening the crystallization conditions.

I agree with Anthony,

Apparently every protein is unique and to be more specific every batch of protein that you purify is not exactly same. So, crystallization trials vary from protein to protein.

To begin with, you can try crystallizing your protein with the conditions which was used to crystallize other amylase before.

Alternatively just try grid screening with Jena or Hampton screen.

This will most probably give you a starting point for you to expand and optimize the crystallization condition.

Good Luck!

Thank u very much.