Table 1.

Constants for inhibition of RNase A catalysis by compounds 1–7

Compound	Ki (mm), no salta	Ki (mm), 0.10 m saltb
Tetraphosphodiester 1	> 10	ND
Tetrasulfonimide 2	0.11 ± 0.02	8.3 ± 1.7
Tetrasulfonimide 3	0.33 ± 0.07	∼ 10
N-acylsulfonamide 4	ND	5.3 ± 0.5
N-acylsulfonamide 5	ND	4.8 ± 0.3
N-acylsulfonamide 6	ND	0.46 ± 0.03
N-acylsulfonamide 7	ND	0.37 ± 0.01

^aValues (±standard error) in 0.05 m Bistris/HCl buffer at pH 6.0.

^bValues (±standard error) in 0.05 m Mes/NaOH buffer at pH 6.0, containing NaCl (0.10 m).