Table 1.

The Effect of the Ala336Pro Mutation on Protease Inhibition Stoichiometries of Inhibition and Association Rate Constants Were Determined against Bovine α-Chymotrypsin at 25°C

Variant	SI*	kass (M/s)	kass·SI (M/s)	Notional Rate† (%)
ATM	1.0	2.65 ± 0.13 × 105	2.65 × 105	100
ATZ	1.5	0.93 ± 0.10 × 105	1.40 × 105	3.5
ATA336P	2.7	0.13 ± 0.03 × 105	0.35 × 105	1.0

Definition of abbreviations: AT_A336P, alpha-1 antitrypsin Ala336Pro (Baghdad variant); AT_M, wild-type alpha-1 antitrypsin (M variant); AT_Z, alpha-1 antitrypsin Glu342Lys (Z variant); k_ass, association rate constant; SI, stoichiometries of inhibition.

^*Standard errors were <5% (calculated from three independent experiments).

^†Calculated as the rate of inhibition (per s) relative to AT_M at a typical concentration (2, 0.2, and 0.4 mg/ml for AT_M, AT_Z, and AT_A336P, respectively) if this were entirely circulating as native monomer.