Try to change the concentration of salt. It is not sure, but sometimes it works. It will depend on the nature of the aggregations forces. Low concentrations of Tween can also help. But you have to try experimentally. Good luck

Proteins from Pichia supernatant can be purified by hydrophobic chromatography by adding ammonium sulfate to the sample and then running, for example, a Butyl resin (look at Tosohas).

I would recommend subtle changes on either the ionic strength and/or pH using general information about the basic physico-chemical properties of the target polypeptide(s) if the information is available.

Try using a sonicating water bath. It is gentle and will not denature proteins.

You might also want to add some mild detergents such a 0.1% octylglucoside or Tween-20.

I think maybe the precipitation with ammonium sulphate could help in this problem... Does anyone have a protocol for ammonium sulphate precipitation to send me, please? I've been trying the ionic exchange, however, the protein activity is in the void of the chromatography...Thanks to all!

The solubility of protein of interest can be enhanced by adding substrate/inhibitor or a ligand. This results in de-aggregation of the target protein.

Good Luck

Either use level of alkali in buffer more than 1.25% or use ammonium sulphate  as a precipitator. Protein disaggregation can be done by using by molecular chaperones.misfolding is to reactivate vital proteins from aggre- gates.Hsp104 facilitates disaggregation and reactivates aggregated

Use  protein concentrators or filters with appropriate NMWL filter(Merk, BioRad etc.), like if u have a 20 kd protein run it  through a 30kd  NMWL filter, all protein come in elute, except proteins smaller than 30kd. So you will left with your protein in filter(not in elute), re-concentrate it. In my experience pichia secrete few big sized proteins and almost none of small protein. So you will be fine otherwise repeat the procedure with lower NMWL(