(40) Assay Card

General Information
Summary Ki calculated for a range of SFTI-1 analogues against trypsin and chymotrypsin.
Condition A solution of bovine trypsin (Boehringer) was incubated for 5 min with inhibitor. The assays were carried out at 20¬¬C in tris(hydroxymethyl)aminomethane (Tris)/HCl buffer (pH 7.8, 100 mM) that contained 10 mM CaCl2. The substrate was N-alpha-benzoyl-L-arginin-4-nitroanilide (0.32 mM) and the initial reaction rate was monitored over 30 min at 405 nm. Determination of anti-chymotrypsin activity: As above, except the substrate was N-succinyl-L-alanyl-L-alanyl-L-prolyl-L-phenylalanin-4-nitroanilide (55 uM).
Result Ki against trypsin and chymotrypsin [nM] as follows: SFTI-1 13±5 and 2300±100, RCTKSIPPICF 11±3 and 6600±240, TKSIPPI 103±7 and >100000, AKSIPPI 1000±80 and NA, TASIPPI >1000 and NA, TKAIPPI 730±40 and NA, TKSAPPI 1920±40 and NA, TKSIAPI >25000 and NA, TKSIPAI 114±6 and NA, TKSIPPA 740±40 and NA, TYSIPPI >25000 and 4500±200, TWSIPPI >20000 and 1400±150, TFSIPPI >20000 and 4800±270.
AssayType Protease inhibition

References
Descours A, Moehle K, Renard A, Robinson JA (2002) A new family of beta-hairpin mimetics based on a trypsin inhibitor from sunflower seeds. Chembiochem 3:318-23

Cross-references
Proteins Assayed SFTI-1
PP-SFTI-2
PP-SFTI-3
PP-SFTI-4
PP-SFTI-5
PP-SFTI-6
PP-SFTI-7
PP-SFTI-8
PP-SFTI-9
PP-SFTI-10
PP-SFTI-11
PP-SFTI-12
PP-SFTI-13