Table 1.

Folding rate of RNase A ^a

Catalyst	Appearance of 50% of 4S (min)	4Sb
Spontaneous folding	400	1
PDI	27	17
PDIΔ455–457	70	4.3
PDI F449R	220	1.5
PDI abb′	200	1.9
PDI domain a	>420	0.6
PDI domain a′	>420	0.6

^a Derived from data in Figures 3 ▶–8 ▶. Reactions were carried out in the presence of 10 μM catalyst. See figure legends for detailed conditions.

^b The rate of formation of 4S species relative to the spontaneous folding at a time point when 35% of 4S had been formed. This rate was found to be linear in all the reactions except that catalyzed by wild-type PDI. This nonlinearity was probably the result of PDI being limited in the other reaction steps.