In my view Sangon Biotech is a good choice. 

Thank you Libing Fu

I will contact them.

You could contact Crelux, they might be able to help you.

http://www.crelux.com/our-solutions/#prime-protein

Is it a viral or bacterial protein?

It is bacterial and therefore could be expressed by E.coli, you could try to contact: http://www.giottobiotech.com/ 

in generall they are quite cheap. 

good luck

Manuele

Thanks Manuele

I'll check them out.