Table 1.

SCCA1 RSL mutants

Serpin	RSL hinge*							RSL variable													kass (105 M−1⋅s−1)†
	P 15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	1′	2′	3′	4′	5′	catS	catG	try	CT
Wild types
SCCA2	G	V	E	A	A	A	A	T	A	V	V	V	V	E	L	S	S	P	S	T	0	1.0‡	0	0
SCCA1	G	A	E	A	A	A	A	T	A	V	V	G	F	G	S	S	P	T	S	T	1.0§	0	0	0
Mutants
AlaP14Arg	.	R	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	0	0		0
AlaP14Thr	.	T	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	3.9	0		0
SCCA1(2)	.	V	.	.	.	.	.	.	.	.	.	V	V	E	L	S	S	P	.	.	0	0.7
SCCA2(1)¶	.	A	.	.	.	.	.	.	.	.	.	G	F	G	S	S	P	T	.	.	1.2	0
GlyP2Arg	.	.	.	.	.	.	.	.	.	.	.	.	.	R	.	.	.	.	.	.	0.2	0	0.4	0
GlyP2Glu	.	.	.	.	.	.	.	.	.	.	.	.	.	E	.	.	.	.	.	.	1.1	0
PheP3Ala	.	.	.	.	.	.	.	.	.	.	.	.	A	.	.	.	.	.	.	.	0	0
PheP3Leu	.	.	.	.	.	.	.	.	.	.	.	.	L	.	.	.	.	.	.	.	3.3	0		0
ThrP3′Ala	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	.	A	.	.	0.9	0		0

^*Schecter and Berger numbering scheme (13), but, for comparative purposes, numbering relative to conserved P15Gly. 

^†catS, cathepsin S; catG, cathepsin G; try, trypsin; CT, chymotrypsin. Second-order rate constants were calculated under second-order conditions (catG) and pseudo-first-order conditions (catS and trypsin). 0, no inhibition seen under conditions used. 

^‡Ref. 12. 

^§Ref. 11. 

^¶SCCA2 framework with SCCA1 RSL.