Lane 1: MB-1TrpHis 0 min;

Lane 2: MB-1TrpHis 30 min;

Lane 3: E44V45 0 min;

Lane 4: E44V45 30 min;

Lane 5: E44M45 0 min;

Lane 6: E44M45 30 min;

Lane 7: D44I45 0 min;

Lane 8: D44I45 30 min;

Lane 9: D44F45 0 min;

Lane 10: D44F45 30 min;

Lane 11: protein Western markers band of 15, 25, 35, 50, 75, 100 and 150kDa;

Lane 12: MB-1TrpHis 0 min;

Lane 13: MB-1TrpHis 30 min;

Lane 14: D44M45 0 min;

Lane 15: D44M45 30 min;

Lane 16: E44F45 0 min;

Lane 17: E44F45 30 min;

Lane 18: D44V45 0 min;

Lane 19: D44V45 30 min.

Proteolysis was performed before cleavage of MBP-MB-1Trp mutant fusions.