Table 1.

Kinetic and thermodynamic parameters derived from amide H/D exchange experiments for subtilisin and for various subtilisin-lactose conjugates.

Subtilisin-Lactosea	A1b	kHX,1 (min−1)	A2b	kHX,2 (min−1)	ΔGHX,1c (kcal/mol)	(ΔGHX,1)−1 d (mol/kcal)
0.0 ± 0.0	0.52	1.39	0.48	0.0008	2.43	0.411
1.0 ± 0.1	0.40	1.40	0.60	0.0005	2.43	0.412
2.2 ± 0.1	0.28	1.19	0.72	0.0004	2.52	0.397
3.5 ± 0.6	0.16	0.27	0.83	0.0002	3.32	0.301

^aAverage moles of lactose bound per mol of subtilisin.

^bA_i is the fraction of amide protons that exchange with the rate constant k_HX,i.

^cGibbs free-energy of unfolding per mol of peptide hydrogen.

^dProtein mobility.