[ccp4bb] problem in heavy metal soaking

[Seema Nath]

I'm working with a protein which crystallizes in a mixture of PEG6K with 0.2M 
AmSO4,my question is if there's any problem if I want to soak heavy metal 
derivatives in this crystallizing condition? Does AmSO4 interfere in 
heavy-metal soaking ? if yes, what's the reason?
Thank you in advance.