New mechanism-based inactivators of trypsin-like proteinases. Selective inactivation of urokinase by functionalized cyclopeptides incorporating a sulfoniomethyl-substituted m-aminobenzoic acid residue.
In order to obtain selective suicide substrates of trypsin-like proteases including plasminogen activators, plasmin, and thrombin, a series of cyclopeptides cyclo[Arg or Lys-aB(CH2X)-Gly4], in which a substituted o- or m-aminobenzoyl group constitutes a latent electrophile, have been prepared. Treatment of the corresponding phenyl ethers cyclo[P1-aB(CH2OC6H5)-Gly4] with HBr/HOAc or R1R2S/TFA gives the bromides (X = Br) or the sulfonium salts (X = +SR1R2 with R1 = R2 = Me or R1 = Me and R2 = C6H5), respectively. These water-soluble cyclopeptides behave as time-dependent inhibitors of bovine trypsin and human urokinase (u-PA) but have no effect on tissue plasminogen activator (t-PA) and no or poor effect on plasmin and thrombin. The compounds containing a m-aminobenzoic acid residue are more efficient inactivators than their anthranilic analogues. The kinetic criteria expected for a suicide inhibition are met. A mechanism of inhibition involving the formation of a quinonimmonium methide intermediate is proposed. The activity of the inhibitors is very sensitive to the nature of the X benzylic substituent. An increased efficiency for the inactivation of human urokinase is observed with the sulfonium salts. The selectivity of the inactivation of u-PA compared to t-PA could be of therapeutical significance in controlling cell proliferation and invasion.
Wakselman
M
M
CNRS-CERCOA, Thiais, France.
Xie
J
J
Mazaleyrat
J P
JP
Boggetto
N
N
Vilain
A C
AC
Montagne
J J
JJ
Reboud-Ravaux
M
M
D062365:Aminobenzoates; D000818:Animals; D002417:Cattle; D006801:Humans; D007700:Kinetics; D008956:Models, Chemical; D010456:Peptides, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D015842:Serine Proteinase Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013452:Sulfonium Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D013552:Swine; D014568:Urokinase-Type Plasminogen Activator / Q000037:antagonists & inhibitors; D062368:meta-Aminobenzoates
D062365:Aminobenzoates; D010456:Peptides, Cyclic; D015842:Serine Proteinase Inhibitors; D013452:Sulfonium Compounds; D062368:meta-Aminobenzoates; D014568:Urokinase-Type Plasminogen Activator; C044855:3-aminobenzoic acid