RESUMO
Novel elongated and shortened derivatives of the peptidomimetic furin inhibitor phenylacetyl-Arg-Val-Arg-4-amidinobenzylamide were synthesized. The most potent compounds, such as Nα (carbamidoyl)Arg-Arg-Val-Arg-4-amidinobenzylamide (Ki =6.2â pm), contain additional basic residues at the Nâ terminus and inhibit furin in the low-picomolar range. Furthermore, to decrease the molecular weight of this inhibitor type, compounds that lack the P5 moiety were prepared. The best inhibitors of this series, 5-(guanidino)valeroyl-Val-Arg-4-amidinobenzylamide and its P3 tert-leucine analogue displayed Ki values of 2.50 and 1.26â nm, respectively. Selected inhibitors, together with our previously described 4-amidinobenzylamide derivatives as references, were tested in cell culture for their activity against furin-dependent infectious pathogens. The propagation of the alphaviruses Semliki Forest virus and chikungunya virus was strongly inhibited in the presence of selected derivatives. Moreover, a significant protective effect of the inhibitors against diphtheria toxin was observed. These results confirm that the inhibition of furin should be a promising approach for the short-term treatment of acute infectious diseases.
Assuntos
Benzamidas/farmacologia , Furina/antagonistas & inibidores , Oligopeptídeos/farmacologia , Peptidomiméticos/farmacologia , Inibidores de Serina Proteinase/farmacologia , Animais , Antivirais/síntese química , Antivirais/farmacologia , Benzamidas/síntese química , Linhagem Celular , Vírus Chikungunya/efeitos dos fármacos , Chlorocebus aethiops , Cricetinae , Toxina Diftérica/metabolismo , Furina/metabolismo , Oligopeptídeos/síntese química , Peptidomiméticos/síntese química , Vírus da Floresta de Semliki/efeitos dos fármacos , Inibidores de Serina Proteinase/síntese químicaRESUMO
The proprotein convertase furin is a potential target for drug design, especially for the inhibition of furin-dependent virus replication. All effective synthetic furin inhibitors identified thus far are multibasic compounds; the highest potency was found for our previously developed inhibitor 4-(guanidinomethyl)phenylacetyl-Arg-Tle-Arg-4-amidinobenzylamide (MI-1148). An initial study in mice revealed a narrow therapeutic range for this tetrabasic compound, while significantly reduced toxicity was observed for some tribasic analogues. This suggests that the toxicity depends at least to some extent on the overall multibasic character of this inhibitor. Therefore, in a first approach, the C-terminal benzamidine of MI-1148 was replaced by less basic P1 residues. Despite decreased potency, a few compounds still inhibit furin in the low nanomolar range, but display negligible efficacy in cells. In a second approach, the P2 arginine was replaced by lysine; compared to MI-1148, this furin inhibitor has slightly decreased potency, but exhibits similar antiviral activity against West Nile and Dengue virus in cell culture and decreased toxicity in mice. These results provide a promising starting point for the development of efficacious and well-tolerated furin inhibitors.
Assuntos
Antivirais/farmacologia , Inibidores Enzimáticos/farmacologia , Furina/antagonistas & inibidores , Animais , Antivirais/síntese química , Antivirais/química , Células Cultivadas , Vírus da Dengue/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Furina/metabolismo , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Estrutura Molecular , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade , Especificidade por Substrato , Vírus do Nilo Ocidental/efeitos dos fármacosRESUMO
Several new analogs of the known thrombin inhibitor NAPAP were synthesized, in which the P2 glycine residue was substituted by natural and unnatural amino acids. The thrombin inhibitory potency was comparable to that of NAPAP. Several of the compounds had inhibition constants lower than 10 nM and a very high selectivity compared to trypsin, factor Xa and plasmin. In addition, analogs were prepared by alkylation of the N(alpha)-atom of the 4-amidinophenylalanine in P1 position, which showed a more than 10-fold lower thrombin inhibition. Furthermore, azaglycine was introduced instead of P2 glycine. For most of the inhibitors similar fast elimination rates were seen in rats after intravenous dosing, as found previously for NAPAP. Only some compounds, which contained a second basic group showed a slightly decreased cumulative biliary clearance.
Assuntos
Antitrombinas/química , Dipeptídeos/química , Piperidinas/química , Pteridinas/química , Antitrombinas/farmacologia , Dipeptídeos/farmacologia , Inibidores do Fator Xa , Fibrinolisina/antagonistas & inibidores , Cinética , Estrutura Molecular , Piperidinas/farmacologia , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Pteridinas/farmacologia , Sensibilidade e Especificidade , Relação Estrutura-Atividade , Inibidores da Tripsina/química , Inibidores da Tripsina/farmacologiaRESUMO
A series of 4-amidinobenzylamine-based peptidomimetic inhibitors of urokinase was synthesized. The most potent one, benzylsulfonyl-D-Ser-Ala-4-amidinobenzylamide 16, inhibits uPA with a K(i) of 7.7 nM but is less selective than 10 with a Gly as P2 residue. Hydroxyamidine and carbonate prodrugs were prepared, which are rapidly converted into the active inhibitors in rats after subcutaneous application.