TABLE 4.

Second order rate constants for the interactions between l-ANT and thrombin in the absence and presence of optimal concentration of heparin

The apparent second order rate constants (k_app) were determined from the slope of the linear plot of k_obs versus inhibitor concentration. The product of k_app × SI represents the second order rate constant (k₂) corrected for SI values.

l-ANT variants	Rate of thrombin inhibition			Rate of thrombin inhibition + LMW			Rate of thrombin inhibition + HMW
	kapp	SI	k2 (kapp × SI)	kapp	SI	k2 (kapp × SI)	kapp	SI	k2 (kapp × SI)
	m−1 s−1		m−1 s−1	m−1 s−1		m−1 s−1	m−1 s−1		m−1 s−1
WT	3.3 ± 0.1 × 102	1.5 ± 0.1	5.0 × 102	1.3 ± 0.1 × 103	2.2 ± 0.1	2.9 × 103	1.8 ± 0.1 × 104	2.5 ± 0.1	4.5 × 104
P1R	4.7 ± 0.1 × 105	1.6 ± 0.1	7.5 × 105	1.9 ± 0.2 × 106	2.8 ± 0.2	5.3 × 106	∼4.7 ± 0.5 × 106	2.9 ± 0.2	1.4 × 107