TABLE 1.

Relative rates of cleavage of HCV 229E 3CL^pro peptide substrates

Cleavage sitea	Peptide	Sequenceb																(Vmax/Km)relc
		P8	P7	P6	P5	P4	P3	P2	P1		P1′	P2′	P3′	P4′	P5′	P6′	P7′
MP1/3CLpro	SP1	V	S	Y	G	S	T	L	Q	↓	A	G	L	R	K	M	A	1.00
3CLpro/MP2	SP4	Q	M	F	G	V	N	L	Q	↓	S	G	K	T	T	S	M	1.17
p23/p12	SP5	C	E	R	V	V	K	L	Q	↓	N	N	E	I	M	P	G	0.09
p12/p16	SP6	I	G	A	T	V	R	L	Q	↓	A	G	K	Q	T	E	F	0.51

^aMP1, putative membrane protein 1 (10, 13, 20); 3CL^pro, 3C-like proteinase (44, 45); MP2, putative membrane protein 2 (10, 13, 20); p23, ORF 1a-encoded, 23-kDa processing product (this study); p12, ORF 1a-encoded, 12-kDa processing product (this study); p16, ORF 1a-encoded, 16-kDa processing product (this study). 

^bAmino acids flanking the proteinase cleavage sites are designated according to the scheme introduced by Schechter and Berger (36). The residues are numbered toward the carboxyl terminus as follows: P3-P2-P1↓P1′-P2′-P3′. 

^cRelative V_max/K_m values were determined by using competition experiments as described in Materials and Methods with SP1 as the reference peptide.