[Fazlil]

Why protiens are precipitated at their isoelectric point?

[SunilNagpal]

Why protiens are precipitated at their isoelectric point?

At isoelectric point there is no net charge on a protein.

At any other pH there remains a net electric charge on a protein which enables it to interact with water (or other related solvents i.e polar solvents). So, if a protein lacks a charge, it will not interact with the solvent (assuming it is polar); which in turn will lead to over powering of protein-protein interactions as compared to protein-water (or polar solvent) interactions; thereby leading to precipitation.

[vishu272]

There must be defined nature of solvent , as water is a polar solvent and in above answer it should be mentioned other related solvents as 'polar solvents'. In non-polar solvents protein may not precipitate at their isoelectric ph

[ForumsEditor]

There must be defined nature of solvent , as water is a polar solvent and in above answer it should be mentioned other related solvents as 'polar solvents'. In non-polar solvents protein may not precipitate at their isoelectric ph

Completely agree!..editing it to clearly put related (to water) solvents as Polar solvents...

(@SunilNagpal, I just put an extra information regarding "Polar solvents" as the exact term for your citation of solvents related to Water)