In a protein stability study, three solutions, MoIA (10 kDa) at 0.5 mM , MoIB (20 kDa) at 0.5 mM , and MolC (20 kDa) at 1 mM , were subjected to denaturation by urea, SDS and guanidium hydrochloride (GnHCl), respectively. The profiles of the fraction of unfolded protein with increasing concentration of the denaturants is given below.
Which one of the following corresponds to reaction conditions at which the number of molecules of folded protein are equal, assuming the reaction volumes to be the same for all experiments?
1
0.2 M urea; 0.05% SDS; 4.5 M GnHCl
2
2 M urea; 0.05% SDS; 1 M GnHCl
3
0.2 M urea; 0.25% SDS; 4.5 M GnHCl
4
2 M urea; 0.25% SDS; 1 M GnHCl