stability can be mean several things - are you referring to delta G of folding or loss of activity over time?

thanks for u r answers. i want to know the stability with respect to delta G of folding and unfolding of proteins.

Preferred:

Denaturation by titration with urea followed by CD in the far UV

Greenfield NJ (2006) Determination of the folding of proteins as a function of denaturants, osmolytes or ligands using circular dichroism. Nat Protoc 1: 2733–2741. doi: 10.1038/nprot.2006.229.

the near UV region is difficult to interpret in terms of structural changes, i would recommend using the far UV

Alternatively:

Differential scanning calorimetry or thermal denaturation followed by SYPRO Orange or ANS fluorescence

Thank you