RESUMEN
Inhibition of the proteasome, the multicatalytic protease complex responsible for the turnover of many cellular proteins, represents an attractive target in the development of new drug therapies, proteasome inhibitors being potentially useful tools for the treatment of pathologies such as cancer, as well as inflammatory, immune and neurodegenerative diseases. Based on our previous development of a new class of inhibitors bearing a C-terminal VE cluster able to interact with catalytic threonine, we report herein the synthesis and activity of new VE-based peptide analogs bearing an additional allyl pharmacophore unit at the C- or N-terminal position of the pseudotripeptide sequence. In the new series, the structural modification carried out to the prototype determine a decrease of proteasome inhibition.
Asunto(s)
Compuestos Alílicos/síntesis química , Compuestos Alílicos/farmacología , Oligopéptidos/síntesis química , Oligopéptidos/farmacología , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasoma , Humanos , Relación Estructura-ActividadRESUMEN
Here we report the study of a new series of vinyl ester cyclopeptide analogues synthesized on the basis of our previous development of a class of cyclopeptides derived from our linear prototype inhibitors. In these compounds, the exocyclic pharmacophoric unit Leu-VE was linked to the gamma-carboxyl group of the glutamic acid residue at the C-terminal. The best analogues of the series have been shown to inhibit the caspase-like activity of the proteasome at nanomolar concentrations and have also demonstrated good resistance to proteolysis and a capacity to permeate the cell membrane.
Asunto(s)
Péptidos Cíclicos/química , Inhibidores de Proteasas/química , Inhibidores de Proteasoma , Secuencia de Aminoácidos , Línea Celular , Semivida , Humanos , Péptidos Cíclicos/farmacocinética , Inhibidores de Proteasas/farmacocinética , Complejo de la Endopetidasa Proteasomal/metabolismoRESUMEN
The synthesis and biological properties of vinyl ester peptide-based molecules bearing linear N-terminal amino acids are reported. Compounds were tested in vitro for their capacity to inhibit the chymotryptic-, tryptic-like, and post-acidic activities of the proteasome. Some analogues showed selective inhibition of post-acidic (PGPH) activity, which is attributed to the beta1 subunit. Interestingly, active compounds demonstrated higher inhibitory activity toward 'standard' proteasomes than toward immunoproteasomes. The inhibitory potency was found to be related to the amino acidic sequence and to the length of the N-terminal residues. The new inhibitors demonstrated resistance to plasmatic proteases and a good capacity to permeate the cell membrane.
Asunto(s)
Péptidos/química , Péptidos/farmacología , Complejo de la Endopetidasa Proteasomal/metabolismo , Inhibidores de Proteasoma , Secuencia de Aminoácidos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Leucocitos Mononucleares/enzimología , Péptidos/síntesis química , Relación Estructura-ActividadRESUMEN
In the present study we describe the synthesis and biological evaluation of 24 analogues of the urotensin II (U-II) fragment U-II(4-11) substituted in position 4 with coded and non-coded aromatic amino acids. All of the new analogues behaved as full U-II receptor (UT) agonists. Our results indicated that aromaticity is well tolerated, size, length and chirality of the side chain are not important, while substituents with a nitrogen atom are preferred. Thus acylation of U-II(5-11) with small groups bearing nitrogen atoms could be instrumental in future studies for the identification of novel potent UT receptor ligands.
Asunto(s)
Aminoácidos , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Urotensinas/química , Urotensinas/metabolismo , Aminoácidos/química , Aminoácidos/metabolismo , Animales , Aorta/anatomía & histología , Aorta/fisiología , Calcio/metabolismo , Línea Celular , Humanos , Ligandos , Masculino , Estructura Molecular , Contracción Muscular/fisiología , Fragmentos de Péptidos/genética , Ratas , Ratas Sprague-Dawley , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismo , Relación Estructura-Actividad , Urotensinas/genética , Vasoconstricción/fisiologíaRESUMEN
The 20S proteasome is a multicatalytic protease complex responsible for the degradation of many proteins in mammalian cells. Specific inhibition of proteasome enzymatic subunits represents a topic of great interest for the development of new drug therapies. Following our previous development of a new class of peptide-based inhibitors bearing a C-terminal vinyl ester residue as a pharmacophoric unit that are able to interact with the catalytic threonine, we report here the synthesis and biological properties of a new series of vinyl ester cyclopeptide analogues. Some of these derivatives were shown to inhibit the chymotrypsin-like activity of the proteasome at nanomolar concentration and their potency was found to depend on the size of the tetrapeptidic cyclic portion.
Asunto(s)
Ésteres/química , Péptidos Cíclicos/síntesis química , Inhibidores de Proteasas/farmacología , Inhibidores de Proteasoma , Compuestos de Vinilo/síntesis química , Cromatografía Líquida de Alta Presión , Quimotripsina/metabolismo , Ciclización , Endopeptidasas/metabolismo , Humanos , Espectroscopía de Resonancia Magnética , Modelos Químicos , Estructura Molecular , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/química , Conformación Proteica , Espectrometría de Masa por Ionización de Electrospray , Tripsina/metabolismo , Compuestos de Vinilo/química , Compuestos de Vinilo/farmacologíaRESUMEN
Here we report the synthesis and biological properties of peptide-based molecules bearing constrained analogues of phenylalanine at the C-terminal. Compounds were tested as proteasome subunits' inhibitors. Dehydro-peptides showed good inhibition, in particular against trypsin-like (T-L) proteasome activity while some C-terminal Tic-derivatives inhibit only caspase-like activity in enzymatic beta1 subunits with a certain degree of efficacy. The best analogues of the series demonstrated good resistance to proteolysis and a capacity to permeate the cell membrane.
Asunto(s)
Inhibidores de Cisteína Proteinasa/farmacología , Fenilalanina/química , Inhibidores de Proteasoma , Línea Celular , Inhibidores de Cisteína Proteinasa/química , Estabilidad de Enzimas , Humanos , Espectroscopía de Resonancia Magnética , Complejo de la Endopetidasa Proteasomal/metabolismoRESUMEN
Here we report the study of a new series of peptide-based proteasome inhibitors with a vinyl ester moiety at C-terminal. The presence of Tic, a rigid analogue of phenylalanine, in the central portion of some derivatives is not favourable for the activity. The best analogue of the series shows a potent and selective inhibition for the beta2 subunit and good enzymatic stability.
Asunto(s)
Inhibidores de Cisteína Proteinasa/farmacología , Glutamina/farmacología , Inhibidores de Proteasoma , Tripsina/efectos de los fármacos , Ésteres , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Tripsina/químicaRESUMEN
The proteasome is a multicatalytic proteinase complex which plays a central role in intracellular protein degradation. We report here the synthesis and biological activities of a new class of specific proteasome inhibitors selective for trypsin-like activity. These tripeptide-based compounds bearing a C-terminal vinyl ester are nontoxic, and do not affect cell proliferation, but are able to modulate the generation and presentation of immunogenic peptides presented by MHC class I molecules.
Asunto(s)
Oligopéptidos/síntesis química , Inhibidores de Proteasoma , Inhibidores de Tripsina/síntesis química , Compuestos de Vinilo/síntesis química , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Epítopos , Ésteres/síntesis química , Ésteres/química , Ésteres/farmacología , Antígeno HLA-A2/metabolismo , Herpesvirus Humano 4/inmunología , Humanos , Oligopéptidos/química , Oligopéptidos/farmacología , Relación Estructura-Actividad , Linfocitos T Citotóxicos/inmunología , Inhibidores de Tripsina/química , Inhibidores de Tripsina/farmacología , Compuestos de Vinilo/química , Compuestos de Vinilo/farmacologíaRESUMEN
The 26S proteasome is a multicatalytic protease complex that plays an essential role in intracellular protein degradation. We have synthesized and tested a series of arecoline peptide derivatives where the peptide portion derives from a screening of tripeptide sequences, and the arecoline moiety has been considered as a potential substrate for catalytic threonine. Derivatives 17-19 are the best compounds of the series, showing chymotryptic-like (beta5) inhibition (IC(50) congruent with 1 microM) and favorable pharmacokinetic properties.
Asunto(s)
Arecolina/análogos & derivados , Arecolina/síntesis química , Cisteína Endopeptidasas/metabolismo , Inhibidores Enzimáticos/síntesis química , Complejos Multienzimáticos/metabolismo , Oligopéptidos/síntesis química , Arecolina/farmacología , Cisteína Endopeptidasas/sangre , Cisteína Endopeptidasas/química , Inhibidores de Cisteína Proteinasa/síntesis química , Inhibidores de Cisteína Proteinasa/farmacología , Estabilidad de Medicamentos , Inhibidores Enzimáticos/farmacología , Humanos , Complejos Multienzimáticos/sangre , Complejos Multienzimáticos/química , Oligopéptidos/farmacología , Complejo de la Endopetidasa ProteasomalRESUMEN
Because of the encouraging results obtained using vinyl ester derivatives, we synthesized and tested a novel series of peptide-based proteasome inhibitors bearing a new pharmacophore unit at the C-terminal. N-Acylpyrrole moiety is a potential substrate for Michael addition by catalytic threonine. Several analogues have demonstrated a selective inhibition of the multicatalytic complex beta1 subunits, the capacity to permeate cellular membrane, and good pharmacokinetics properties.
Asunto(s)
Oligopéptidos/síntesis química , Inhibidores de Proteasoma , Pirroles/síntesis química , Compuestos de Vinilo/síntesis química , Antineoplásicos/síntesis química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Dominio Catalítico , Línea Celular Tumoral , Permeabilidad de la Membrana Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Estabilidad de Medicamentos , Humanos , Modelos Moleculares , Oligopéptidos/farmacocinética , Oligopéptidos/farmacología , Complejo de la Endopetidasa Proteasomal/sangre , Complejo de la Endopetidasa Proteasomal/química , Subunidades de Proteína/antagonistas & inhibidores , Pirroles/farmacocinética , Pirroles/farmacología , Relación Estructura-Actividad , Compuestos de Vinilo/farmacocinética , Compuestos de Vinilo/farmacologíaRESUMEN
Two small libraries of tripeptidic-based vinyl ester derivative proteasome inhibitors were synthesized and tested, starting with the Hmb-Val-Gln-Leu-VE prototype. The P3 and P4 positions were investigated with a complete set of amino acid residues, some of which showed remarkable selective inhibition of the trypsin-like (beta2) subunit. In both positions, aromatic and hydrophobic residues were preferred.
Asunto(s)
Ésteres/química , Péptidos/química , Péptidos/farmacología , Inhibidores de Proteasoma , Compuestos de Vinilo/química , Secuencia de Aminoácidos , Péptidos/síntesis química , Complejo de la Endopetidasa Proteasomal/metabolismoRESUMEN
A series of N-benzyl pseudopeptides was designed, synthesized and tested as HIV-1 protease inhibitors. The ability of the new compounds containing N-benzyl hydroxyalkylamino acid core structure to inhibit HIV replication in cell culture is comparable to their capacity to inhibit the isolated enzyme, a result compatible with good pharmacokinetic properties of these derivatives. The pseudotripeptide Fmoc-Leu-N(Bzl)Hse-Met-NH-tBu was the best inhibitor of the series (IC(50)=170 nM) showing promising inhibition of viral replication (ED(50)=52 nM). All new compounds exhibit high enzymatic resistance and stability against cell cultures and plasma enzymes.
Asunto(s)
Compuestos de Bencilo/síntesis química , Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/síntesis química , Proteasa del VIH/metabolismo , VIH-1/metabolismo , Péptidos/síntesis química , Compuestos de Bencilo/farmacología , Línea Celular , Inhibidores de la Proteasa del VIH/farmacología , Humanos , Concentración 50 Inhibidora , Modelos Moleculares , Péptidos/farmacología , Replicación Viral/efectos de los fármacosRESUMEN
In order to improve the immunotherapeutical potential of H-Cys-Leu-Gly-Gly-Leu-Leu-Thr-Met-Val-OH (CLG) peptide, an Epstein-Barr virus (EBV) subdominant epitope derived from the membrane protein LMP2, we have synthesized and tested CLG analogues containing cis- and/or trans-4-aminocyclohexanecarboxylic acid (ACCA) replacing Gly-Gly and/or Thr-Met dipeptide units. All pseudopeptides were tested for metabolic stability and for their capacity to bind HLA-A2 molecules and to sensitize target cells to lysis. All new compounds exhibited higher enzymatic resistance compared to the original CLG and some trans-ACCA-derivatives were able to associate HLA-A2 and to efficiently stimulate CTL responses directed against the CLG natural epitope.
Asunto(s)
Aminoácidos Cíclicos/inmunología , Ácidos Ciclohexanocarboxílicos/inmunología , Epítopos/química , Oligopéptidos/inmunología , Linfocitos T Citotóxicos/inmunología , Aminoácidos Cíclicos/química , Aminoácidos Cíclicos/farmacocinética , Ácidos Ciclohexanocarboxílicos/química , Ácidos Ciclohexanocarboxílicos/farmacocinética , Pruebas Inmunológicas de Citotoxicidad , Estabilidad de Medicamentos , Antígeno HLA-A2/inmunología , Herpesvirus Humano 4/inmunología , Humanos , Inmunoterapia , Oligopéptidos/química , Oligopéptidos/farmacocinética , Relación Estructura-Actividad , Células Tumorales Cultivadas , Proteínas de la Matriz Viral/inmunologíaRESUMEN
The synthesis and pharmacological activity of novel nociceptin/orphanin FQ (N/OFQ) analogues modified in the Phe(1)-Gly(2) peptide bond are reported. The aim of the present work was to elucidate the importance of this peptide bond for the N/OFQ receptor (NOP) interaction. Our study indicates that the first peptide bond in N/OFQ is important but not crucial for interaction with the N/OFQ receptor; for instance, substitution with a methyleneoxy bond generates an agonist derivative just 3-fold less potent than the reference compound.
Asunto(s)
Péptidos Opioides/síntesis química , Péptidos Opioides/farmacología , Animales , Estimulación Eléctrica , Glicina/química , Técnicas In Vitro , Ligandos , Masculino , Ratones , Relajación Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Péptidos/química , Fenilalanina/química , Relación Estructura-Actividad , NociceptinaRESUMEN
We describe the synthesis and biological activities of a series of methyl 3,4-epoxypiperidine-3-carboxylate tripeptide derivatives that inhibit the chymotryptic and tryptic active sites of the 20S proteasome. Of the series, compound 2 which contains 3-hydroxy-2-methylbenzoyl group at its N-terminal position, displayed the greatest inhibitory potency (IC(50) <1 microM). All derivatives showed favourable pharmacokinetic properties.
Asunto(s)
Arecolina/química , Complejos Multienzimáticos/antagonistas & inhibidores , Oligopéptidos/síntesis química , Oligopéptidos/farmacología , Inhibidores de Proteasas/síntesis química , Inhibidores de Proteasas/farmacología , Arecolina/análogos & derivados , Quimotripsina/antagonistas & inhibidores , Cisteína Endopeptidasas , Humanos , Estructura Molecular , Oligopéptidos/metabolismo , Inhibidores de Proteasas/metabolismo , Complejo de la Endopetidasa Proteasomal , Relación Estructura-ActividadRESUMEN
The majority of hepatitis C virus (HCV)-infected individuals fail to resolve the infection and become chronically infected despite the presence of HCV-specific CTL responses directed to different HCV-derived peptide antigens. Only a minority of individuals is able to clear the virus by mounting efficient CTL responses early after acute infection, but at present it is not clear whether viral clearance is associated with CTL responses of defined specificity. To elucidate those responses associated with improvement of the disease, we analyzed CTL responses to 16 different HLA-A2-presented, HCV-derived epitopes in 12 chronically infected patients, 14 chronically infected patients treated with interferon-alpha, and in one patient with acute symptomatic disease. We show here that the majority of chronically infected individuals present CTL responses directed to an NS4-derived peptide antigen (amino acids 1789-1797). Treated patients presented stronger HCV-specific CTL responses and therapy-induced changes in CTL target choice. In particular, 13 out of 14 individuals responded to an NS3-derived epitope (amino acids 1073-1081). By longitudinal analysis we show that five individuals responding to IFN-alpha therapy with decreases in alanine aminotransferase levels presented a strong CTL activity directed to the NS3-derived epitope. One patient that spontaneously resolved the infection presented a generally strong CTL activity specific for HCV-derived epitopes with a dominant response to the NS3-derived peptide antigen. This suggests that CTL responses directed to this NS3-derived antigen may be beneficial for the control of HCV infection. Improvement of these responses may represent a therapeutic intervention in chronic HCV infection.