Table 2.

Proportions of the RNase A folding intermediates^a

Catalyst	1S/2S	2S/3S
Spontaneous folding	0.6	1.8
PDI	0b	1.1
PDI Δ455–457	0.5	1.5
PDI F449R	0.5	1.3
PDI abb′	0.6	1.3
PDI domain a	0.7	1.9
PDI domain a′	0.8	1.9

^a Proportions of the folding intermediates were calculated in the presence of 10 μM catalyst at a time point when 35% of the 4S species had been formed. The levels of the 1S, 2S, and 3S intermediates were relatively stable at this point, indicating that the forward and reverse reactions were balanced and that the species were in temporary kinetic equilibrium.

^b No 1S could be detected because of its rapid conversion to 2S.