Table 1.
Alignment of known LF protease cleavage sites within the MKK family (4), the substrate motif (where H = hydrophobic residue and B = basic residue), the resulting consensus sequence, and substrates synthesized for this article
| Substrate | Peptide sequence | |
|---|---|---|
| MEK11–16 | MPKKKPTP | IQLNPAPD |
| MEK23–18 | ARRKPVLP | ALTINPTI |
| MKK3b19–34 | SKRKKDVR | ISCMSKPP |
| MKK6b7–22 | KKRNPGLK | IPKEAFEQ |
| MKK438–53 | QGKRKALK | LNFANPPF |
| MKK451–66 | PPFKSTAR | FTLNPNPT |
| MKK7β37–52 | QRPRPTLQ | LPLANDGG |
| MKK7β69–84 | ARPRHMLG | LPSTLFTP |
| MKK substrate motif | -BBBB-H- | H------- |
| Derived Consensus peptide* | NleKKKKVLP | IQLNAATD |
| (Flu)MEK11–16-NH2 | (Flu)MPKKKPTP | IQLNPAPD-NH2 |
| (Flu)[Nle1]MEK11–16(KGG)-NH2 | (Flu)NlePKKKPTP | IQLNPAPDKGG-NH2 |
| (Flu)Consensus(KGG)-NH2 | (Flu)NleKKKKVLP | IQLNAATDKGG-NH2 |
| (Cou)Consensus(K(QSY-35)GG)-NH2 | (Cou)NleKKKKVLP | IQLNAATDK(QSY-35)GG-NH2 |
| (Cou)Consensus(K(DAB)GG)-NH2 | (Cou)NleKKKKVLP | IQLNAATDK(DAB)GG-NH2 |
| (QSY-35)Consensus(K(Cou)GG)-NH2 | (QSY-35)NleKKKKVLP | IQLNAATDK(Cou)GG-NH2 |
| (DAB)Consensus(K(Cou)GG)-NH2 | (DAB)NleKKKKVLP | IQLNAATDK(Cou)GG-NH2 |
Flu, 5,6-carboxyfluoresceinyl; Cou, 7-hydroxy-4-methyl-3-acetylcoumarinyl; DAB, 4-dimethylaminoazobenzene-4′-carboxyl; QSY-35, N-({4-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]phenyl}acetyl.
*
Denoted “Consensus.”