Inhibitors of Matriptase‐2 Based on the Trypsin Inhibitor SFTI‐1

Abstract

A series of 17 new analogues of trypsin inhibitor SFTI-1 were designed and synthesized to obtain matriptase-2 inhibitors. A number of the modified bicyclic peptides displayed much higher affinity towards matriptase-2 than towards the highly homologous matriptase-1. Replacement of Lys5 by Arg in the wild-type SFTI-1 led to an 11-fold increase in the matriptase-2 inhibitory activity. Replacement of Arg2 by its enantiomer (D-arginine) slightly lowered the inhibition of matriptase-2, but almost completely abolished the affinity towards matriptase-1, thus yielding the most selective matriptase-2 inhibitor. This is the first report describing inhibitors of the recently discovered matriptase-2 based on the SFTI-1 structure. The results showed that SFTI-1 is a promising scaffold for the design of potent and selective inhibitors of this enzyme.

Design and chemical syntheses of potent matriptase‐2 inhibitors based on trypsin inhibitor SFTI‐1 isolated from sunflower seeds

“…[35][36][37] Our results [33] proved that the 14 amino acids containing, bicyclic trypsin inhibitor isolated from sunflower seeds (SFTI-1) [38] can be utilized as a properties, among which are a well-defined 3D structure, a lowmolecular mass and a significant proteolytic resistance. [35][36][37] Our results [33] proved that the 14 amino acids containing, bicyclic trypsin inhibitor isolated from sunflower seeds (SFTI-1) [38] can be utilized as a properties, among which are a well-defined 3D structure, a lowmolecular mass and a significant proteolytic resistance.…”

“…[18] Recombinant human matriptase- Thereafter, the stock solution was diluted 100 times to obtain a proper read-out on the microplate reader. [33] [49] ), assuming competitive inhibition, according to the Cheng-Prusoff equation IC 50 5 K i (11 S/K m ), [50] where IC 50 is the inhibitor concentrations giving 50% inhibition, K i the inhibition constant, [S] the substrate concentration, and K m the Michaelis-Menten constant. The chromogenic substrates for matriptase-1, plasmin, thrombin, and trypsin were purchased from Pepta Nova, Germany, a FRET substrate ABZ-Ile-Arg-Ala-Arg-Ser-Ala-Ala-Tyr(3-NO 2 )-NH 2 (ABZ: 2aminobenzoic acid) for matriptase-2 was synthesized according to Wysocka et al [47] The molar concentration of each peptide for enzymatic assays was determined using analytical HPLC, Shimadzu Prominence, RP Supelco Supelcosil LC-8, 5 lm column (4.6 3 250 mm).…”

“…In a previous study, [33] we reported on 17 analogues of the sunflower trypsin inhibitor-1 (SFTI-1) with different inhibitory potencies toward matriptase-1 and matriptase-2. We proved that bicyclic peptides are better matriptase-2 inhibitors than their monocyclic counterparts-the opposite trend was observed for matriptase-1.…”

“…SFTI-1 is an important and promising scaffold for drug discovery and development of pharmaceuticals. [33] were synthesized on 2-chlorotrityl chloride resin (GL Biochem, Shanghai Ltd.) and the C-terminal amino acid residue Fmoc-Asp(OtBu) was attached to the aforementioned resin as described previously [33,40] (in the presence of an equimolar amount of DIPEA under anhydrous conditions in DCM solution). Herein we describe a series of new analogues of SFTI-1 designed to be matriptase-2 inhibitors.…”

Prospects for the design of new therapeutically significant protease inhibitors based on knottins and sunflower seed trypsin inhibitor (SFTI 1)

“…Известно также, что некоторые аналоги SFTI 1 могут воздействовать и на цистеиновые протеазы протеасом [139]. Пока нет ответов на вопросы, достаточно ли компьютерного моделирования для оценки селективности взаимодействия ингибитора с целевым ферментом; каковы критерии селективности, например, достаточно ли разницы в величинах K i одним и тем же ингибитором матриптазы 2 и матриптазы 1 в 15 раз [140] для селективного торможения одного из двух ферментов; сколько и каких ферментов надо тестировать на взаимодействие с новым ингибитором, чтобы доказать его селективность. К сожалению, отсутствуют данные об активности природных и сконструированных кноттинов-ИСП в экспериментах in vivo, на моделях соответствующих патологических процессов.…”