RESUMO
SARS-CoV-2 and HCoV-OC43 belong to the same ß genus of the Coronaviridae family. SARS-CoV-2 was responsible for the recent COVID-19 pandemic, and HCoV-OC43 is the etiological agent of mild upper respiratory tract infections. SARS-COV-2 and HCoV-OC43 co-infections were found in children with respiratory symptoms during the COVID-19 pandemic. The two ß-coronaviruses share a high degree of homology between the 3CLpro active sites, so much so that the safer HCoV-OC43 has been suggested as a tool for the identification of new anti-SARS-COV-2 agents. Compounds 5 and 24 inhibited effectively both Wuhan and British SARS-CoV-2 patient isolates in Vero E6 cells and the HCoV-OC43 in MRC-5 cells at low micromolar concentrations. The inhibition was apparently exerted via targeting the 3CLpro active sites of both viruses. Compounds 5 and 24 at 100 µM inhibited the SARS-CoV-2 3CLpro activity of 61.78 and 67.30%, respectively. These findings highlight 5 and 24 as lead compounds of a novel class of antiviral agents with the potential to treat SARS-COV-2 and HCoV-OC43 infections.
RESUMO
Apoptosis-inducing factor (AIF), which is confined to mitochondria of normal healthy cells, is the first identified caspase-independent cell death effector. Moreover, AIF is required for the optimal functioning of the respiratory chain machinery. Recent findings have revealed that AIF fulfills its pro-survival function by interacting with CHCHD4, a soluble mitochondrial protein which promotes the entrance and the oxidative folding of different proteins in the inner membrane space. Here, we report the crystal structure of the ternary complex involving the N-terminal 27-mer peptide of CHCHD4, NAD+, and AIF harboring its FAD (flavin adenine dinucleotide) prosthetic group in oxidized form. Combining this information with biophysical and biochemical data on the CHCHD4/AIF complex, we provide a detailed structural description of the interaction between the two proteins, validated by both chemical cross-linking mass spectrometry analysis and site-directed mutagenesis.
Assuntos
Fator de Indução de Apoptose , Domínio Catalítico , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Proteínas Mitocondriais , Modelos Moleculares , Ligação Proteica , Fator de Indução de Apoptose/metabolismo , Fator de Indução de Apoptose/química , Fator de Indução de Apoptose/genética , Humanos , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/química , Proteínas Mitocondriais/genética , Regulação Alostérica , Cristalografia por Raios X , NAD/metabolismo , NAD/química , Sítios de Ligação , Fatores de Transcrição/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/genéticaRESUMO
The stabilization of the retromer protein complex can be effective in the treatment of different neurological disorders. Following the identification of bis-1,3-phenyl guanylhydrazone 2a as an effective new compound for the treatment of amyotrophic lateral sclerosis, in this work we analyze the possible binding sites of this molecule to the VPS35/VPS29 dimer of the retromer complex. Our results show that the affinity for different sites of the protein assembly depends on compound charge and therefore slight changes in the cell microenvironment could promote different binding states. Finally, we describe a novel binding site located in a deep cleft between VPS29 and VPS35 that should be further explored to select novel molecular chaperones for the stabilization of the retromer complex.
RESUMO
Misfolded glycoprotein recognition and endoplasmic reticulum (ER) retention are mediated by the ER glycoprotein folding quality control (ERQC) checkpoint enzyme, UDP-glucose glycoprotein glucosyltransferase (UGGT). UGGT modulation is a promising strategy for broad-spectrum antivirals, rescue-of-secretion therapy in rare disease caused by responsive mutations in glycoprotein genes, and many cancers, but to date no selective UGGT inhibitors are known. The small molecule 5-[(morpholin-4-yl)methyl]quinolin-8-ol (5M-8OH-Q) binds a CtUGGTGT24 "WY" conserved surface motif conserved across UGGTs but not present in other GT24 family glycosyltransferases. 5M-8OH-Q has a 47 µM binding affinity for CtUGGTGT24in vitro as measured by ligand-enhanced fluorescence. In cellula, 5M-8OH-Q inhibits both human UGGT isoforms at concentrations higher than 750 µM. 5M-8OH-Q binding to CtUGGTGT24 appears to be mutually exclusive to M5-9 glycan binding in an in vitro competition experiment. A medicinal program based on 5M-8OH-Q will yield the next generation of UGGT inhibitors.
RESUMO
STUDY OBJECTIVE: We analyzed occupational accidents reported among Corpo Nazionale Soccorso Alpino e Speleologico (CNSAS) providers during mountain search and rescue operations and training events in Italy (1999 to 2019). METHODS: We extracted anonymized data from the CNSAS accident database for all cases of injured mountain search and rescue providers that activated CNSAS insurance (1999 to 2019). We report epidemiological characteristics, mechanisms, type, and severity of injury or illness, clinical outcome, and recovery time. RESULTS: A total of 784 cases of injuries in CNSAS mountain search and rescue providers were recorded. Forty-one percent of the cases occurred during rescue operations and 59% during training events. Overall, trauma was the main cause of injury (96%), whereas only 4% of the cases were classified as medical or environmental illnesses. Moderate injury (National Advisory Committee for Aeronautics II to III) occurred in 80% of the reported accidents. Recovery time differed based on the degree of accident severity. Fatalities occurred in 2% of the cases reported and occurred during rescue operations only. CONCLUSION: In this long-term retrospective analysis, we showed that accidents occurred among mountain search and rescue providers both during rescue operations and training events. Given the high prevalence and associated costs, it is of pivotal importance to understand the epidemiology and characteristics of occupational injury and illness among this out-of-hospital workforce to better inform future prevention strategies.
Assuntos
Trabalho de Resgate , Ferimentos e Lesões , Humanos , Acidentes de Trabalho , Estudos Retrospectivos , Acidentes , Bases de Dados Factuais , ItáliaRESUMO
Pyridobenzothiazolone derivatives are a promising class of broad-spectrum antivirals. However, the mode of action of these compounds remains poorly understood. The HeE1-17Y derivative has already been shown to be a potent compound against a variety of flaviviruses of global relevance. In this work, the mode of action of HeE1-17Y has been studied for West Nile virus taking advantage of reporter replication particles (RRPs). Viral infectivity was drastically reduced by incubating the compound with the virus before infection, thus suggesting a direct interaction with the viral particles. Indeed, RRPs incubated with the inhibitor appeared to be severely compromised in electron microscopy analysis. HeE1-17Y is active against other enveloped viruses, including SARS-CoV-2, but not against two non-enveloped viruses, suggesting a virucidal mechanism that involves the alteration of the viral membrane.
Assuntos
COVID-19 , Flavivirus , Vírus de RNA , Vírus , Antivirais/farmacologia , Humanos , SARS-CoV-2RESUMO
Inhibitors of apoptosis proteins (IAPs) are validated onco-targets, as their overexpression correlates with cancer onset, progression, diffusion and chemoresistance. IAPs regulate cell death survival pathways, inflammation, and immunity. Targeting IAPs, by impairing their protein-protein interaction surfaces, can affect events occurring at different stages of cancer development. To this purpose, we employed a rational virtual screening approach to identify compounds predicted to interfere with the assembly of pro-survival macromolecular complexes. One of the candidates, FC2, was shown to bind in vitro the BIR1 domains of both XIAP and cIAP2. Moreover, we demonstrated that FC2 can induce cancer cell death as a single agent and, more potently, in combination with the Smac-mimetic SM83 or with the cytokine TNF. FC2 determined a prolonged activation of the NF-κB pathway, accompanied to a stabilization of XIAP-TAB1 complex. This candidate molecule represents a valuable lead compound for the development of a new class of IAP-antagonists for cancer treatment.
RESUMO
Gelsolin comprises six homologous domains, named G1 to G6. Single point substitutions in this protein are responsible for AGel amyloidosis, a hereditary disease causing progressive corneal lattice dystrophy, cutis laxa, and polyneuropathy. Although several different amyloidogenic variants of gelsolin have been identified, only the most common mutants present in the G2 domain have been thoroughly characterized, leading to clarification of the functional mechanism. The molecular events underlying the pathological aggregation of 3 recently identified mutations, namely A551P, E553K and M517R, all localized at the interface between G4 and G5, are here explored for the first time. Structural studies point to destabilization of the interface between G4 and G5 due to three structural determinants: ß-strand breaking, steric hindrance and/or charge repulsion, all implying impairment of interdomain contacts. Such rearrangements decrease the temperature and pressure stability of gelsolin but do not alter its susceptibility to furin cleavage, the first event in the canonical aggregation pathway. These variants also have a greater tendency to aggregate in the unproteolysed forms and exhibit higher proteotoxicity in a C. elegans-based assay. Our data suggest that aggregation of G4G5 variants follows an alternative, likely proteolysis-independent, pathway.
RESUMO
Acid-sensitive ion channels (ASICs) are sodium channels partially permeable to Ca2+ ions, listed among putative targets in central nervous system (CNS) diseases in which a pH modification occurs. We targeted novel compounds able to modulate ASIC1 and to reduce the progression of ischemic brain injury. We rationally designed and synthesized several diminazene-inspired diaryl mono- and bis-guanyl hydrazones. A correlation between their predicted docking affinities for the acidic pocket (AcP site) in chicken ASIC1 and their inhibition of homo- and heteromeric hASIC1 channels in HEK-293 cells was found. Their activity on murine ASIC1a currents and their selectivity vs mASIC2a were assessed in engineered CHO-K1 cells, highlighting a limited isoform selectivity. Neuroprotective effects were confirmed in vitro, on primary rat cortical neurons exposed to oxygen-glucose deprivation followed by reoxygenation, and in vivo, in ischemic mice. Early lead 3b, showing a good selectivity for hASIC1 in human neurons, was neuroprotective against focal ischemia induced in mice.
Assuntos
Bloqueadores do Canal Iônico Sensível a Ácido/uso terapêutico , Canais Iônicos Sensíveis a Ácido/metabolismo , Guanidinas/uso terapêutico , Hidrazonas/uso terapêutico , Infarto da Artéria Cerebral Média/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Bloqueadores do Canal Iônico Sensível a Ácido/síntese química , Bloqueadores do Canal Iônico Sensível a Ácido/metabolismo , Canais Iônicos Sensíveis a Ácido/química , Animais , Sítios de Ligação , Células CHO , Galinhas , Cricetulus , Desenho de Fármacos , Guanidinas/síntese química , Guanidinas/metabolismo , Células HEK293 , Humanos , Hidrazonas/síntese química , Hidrazonas/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Estrutura Molecular , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/metabolismo , Ligação Proteica , Ratos , Relação Estrutura-AtividadeRESUMO
The current emergency of the novel coronavirus SARS-CoV2 urged the need for broad-spectrum antiviral drugs as the first line of treatment. Coronaviruses are a large family of viruses that already challenged humanity in at least two other previous outbreaks and are likely to be a constant threat for the future. In this work we developed a pipeline based on in silico docking of known drugs on SARS-CoV1/2 RNA-dependent RNA polymerase combined with in vitro antiviral assays on both SARS-CoV2 and the common cold human coronavirus HCoV-OC43. Results showed that certain drugs displayed activity for both viruses at a similar inhibitory concentration, while others were specific. In particular, the antipsychotic drug lurasidone and the antiviral drug elbasvir showed promising activity in the low micromolar range against both viruses with good selectivity index.
Assuntos
Antivirais/farmacologia , Benzofuranos/farmacologia , Coronavirus Humano OC43/efeitos dos fármacos , Reposicionamento de Medicamentos , Imidazóis/farmacologia , Cloridrato de Lurasidona/farmacologia , SARS-CoV-2/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Chlorocebus aethiops , Simulação por Computador , Fibroblastos , Humanos , Células Vero , Replicação Viral/efeitos dos fármacos , Tratamento Farmacológico da COVID-19RESUMO
Determination of death requires specific knowledge, training, and experience in most cases. It can be particularly difficult when external conditions, such as objective hazards in mountains, prevent close physical examination of an apparently lifeless person, or when examination cannot be accomplished by an authorized person. Guidelines exist, but proper use can be difficult. In addition to the absence of vital signs, definitive signs of death must be present. Recognition of definitive signs of death can be problematic due to the variability in time course and the possibility of mimics. Only clear criteria such as decapitation or detruncation should be used to determine death from a distance or by laypersons who are not medically trained. To present criteria that allow for accurate determination of death in mountain rescue situations, the International Commission for Mountain Emergency Medicine convened a panel of mountain rescue doctors and a forensic pathologist. These recommendations are based on a nonsystematic review of the literature including articles on determination of death and related topics.
Assuntos
Reanimação Cardiopulmonar/métodos , Morte , Montanhismo , Guias de Prática Clínica como Assunto , Trabalho de Resgate/normas , HumanosRESUMO
The guanylyl cyclase-activating protein 1, GCAP1, activates or inhibits retinal guanylyl cyclase (retGC) depending on cellular Ca2+ concentrations. Several point mutations of GCAP1 have been associated with impaired calcium sensitivity that eventually triggers progressive retinal degeneration. In this work, we demonstrate that the recombinant human protein presents a highly dynamic monomer-dimer equilibrium, whose dissociation constant is influenced by salt concentration and, more importantly, by protein binding to Ca2+ or Mg2+. Based on small-angle X-ray scattering data, protein-protein docking, and molecular dynamics simulations we propose two novel three-dimensional models of Ca2+-bound GCAP1 dimer. The different propensity of human GCAP1 to dimerize suggests structural differences induced by cation binding potentially involved in the regulation of retGC activity.
Assuntos
Cálcio/química , Proteínas Ativadoras de Guanilato Ciclase/química , Magnésio/química , Simulação de Dinâmica Molecular , Multimerização Proteica , Cálcio/metabolismo , Proteínas Ativadoras de Guanilato Ciclase/metabolismo , Humanos , Magnésio/metabolismoRESUMO
Protein-protein interactions are the basis of many important physiological processes and are currently promising, yet difficult, targets for drug discovery. In this context, inhibitor of apoptosis proteins (IAPs)-mediated interactions are pivotal for cancer cell survival; the interaction of the BIR1 domain of cIAP2 with TRAF2 was shown to lead the recruitment of cIAPs to the TNF receptor, promoting the activation of the NF-κB survival pathway. In this work, using a combined in silico-in vitro approach, we identified a drug-like molecule, NF023, able to disrupt cIAP2 interaction with TRAF2. We demonstrated in vitro its ability to interfere with the assembly of the cIAP2-BIR1/TRAF2 complex and performed a thorough characterization of the compound's mode of action through 248 parallel unbiased molecular dynamics simulations of 300 ns (totaling almost 75 µs of all-atom sampling), which identified multiple binding modes to the BIR1 domain of cIAP2 via clustering and ensemble docking. NF023 is, thus, a promising protein-protein interaction disruptor, representing a starting point to develop modulators of NF-κB-mediated cell survival in cancer. This study represents a model procedure that shows the use of large-scale molecular dynamics methods to typify promiscuous interactors.
Assuntos
Proteínas Inibidoras de Apoptose , Suramina , Proteínas Inibidoras de Apoptose/metabolismo , NF-kappa B , Suramina/análogos & derivados , Fator 2 Associado a Receptor de TNF/metabolismoRESUMO
Amyotrophic Lateral Sclerosis (ALS) is a fatal disease characterized by the degeneration of upper and lower motor neurons (MNs). We find a significant reduction of the retromer complex subunit VPS35 in iPSCs-derived MNs from ALS patients, in MNs from ALS post mortem explants and in MNs from SOD1G93A mice. Being the retromer involved in trafficking of hydrolases, a pathological hallmark in ALS, we design, synthesize and characterize an array of retromer stabilizers based on bis-guanylhydrazones connected by a 1,3-phenyl ring linker. We select compound 2a as a potent and bioavailable interactor of VPS35-VPS29. Indeed, while increasing retromer stability in ALS mice, compound 2a attenuates locomotion impairment and increases MNs survival. Moreover, compound 2a increases VPS35 in iPSCs-derived MNs and shows brain bioavailability. Our results clearly suggest the retromer as a valuable druggable target in ALS.
Assuntos
Esclerose Lateral Amiotrófica/tratamento farmacológico , Hidrazonas/farmacologia , Neurônios Motores/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Proteínas de Transporte Vesicular/genética , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Diferenciação Celular , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Hidrazonas/síntese química , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Masculino , Camundongos , Camundongos Transgênicos , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/síntese química , Ligação Proteica/efeitos dos fármacos , Multimerização Proteica , Relação Estrutura-Atividade , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/metabolismo , Proteínas de Transporte Vesicular/metabolismoRESUMO
Guanylate cyclase activating protein 1 (GCAP1) is a neuronal calcium sensor (NCS) involved in the early biochemical steps underlying the phototransduction cascade. By switching from a Ca2+-bound form in the dark to a Mg2+-bound state following light activation of the cascade, GCAP1 triggers the activation of the retinal guanylate cyclase (GC), thus replenishing the levels of 3',5'-cyclic monophosphate (cGMP) necessary to re-open CNG channels. Here, we investigated the structural and functional effects of three missense mutations in GCAP1 associated with cone-rod dystrophy, which severely perturb the homeostasis of cGMP and Ca2+. Substitutions affect residues directly involved in Ca2+ coordination in either EF3 (D100G) or EF4 (E155A and E155G) Ca2+ binding motifs. We found that all GCAP1 variants form relatively stable dimers showing decreased apparent affinity for Ca2+ and blocking the enzyme in a constitutively active state at physiological levels of Ca2+. Interestingly, by corroborating spectroscopic experiments with molecular dynamics simulations we show that beside local structural effects, mutation of the bidentate glutamate in an EF-hand calcium binding motif can profoundly perturb the flexibility of the adjacent EF-hand as well, ultimately destabilizing the whole domain. Therefore, while Ca2+-binding to GCAP1 per se occurs sequentially, allosteric effects may connect EF hand motifs, which appear to be essential for the integrity of the structural switch mechanism in GCAP1, and perhaps in other NCS proteins.
Assuntos
Cálcio/metabolismo , Distrofias de Cones e Bastonetes/genética , Proteínas Ativadoras de Guanilato Ciclase/química , Proteínas Ativadoras de Guanilato Ciclase/genética , Mutação de Sentido Incorreto/genética , Difusão Dinâmica da Luz , Proteínas Ativadoras de Guanilato Ciclase/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Cinética , Simulação de Dinâmica Molecular , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Mutação Puntual/genética , Agregados Proteicos , Multimerização Proteica , Estabilidade Proteica , Espalhamento a Baixo Ângulo , Temperatura , Difração de Raios XRESUMO
Skin manifestations of COVID-19 infections are diverse and are new to the dermatology community. We had the opportunity to examine the clinical and histopathological features of several patients who were divided into 3 groups. The first group included 8 COVID-19-positive patients who were hospitalized and quarantined at home. The second group included children and young adults who presented with chilblain erythema, erythema multiforme, and urticaria-like lesions. This group of patients was negative for the COVID-19 gene sequences by polymerase chain reaction but had a high risk of COVID-19 infection. The third group included clinically heterogeneous and challenging lesions. These patients were not subject to either polymerase chain reaction tests or serological analyses because they sought dermatological attention only for a dermatosis. The histopathological analysis of these cases showed a wide spectrum of histopathological patterns. What appears to be constant in all skin biopsies was the presence of prominent dilated blood vessels with a swollen endothelial layer, vessels engulfed with red blood cells, and perivascular infiltrates, consisting mainly of cytotoxic CD8+ lymphocytes and eosinophils. In 2 cases, there was diffuse coagulopathy in the cutaneous vascular plexus. In the early phases of the disease, there were numerous collections of Langerhans cells in the epidermis after being activated by the virus. The presence of urticarial lesions, chilblains, targetoid lesions (erythema multiforme-like lesions), exanthema, maculohemorrhagic rash, or chickenpox-like lesions associated with the histopathological features mentioned previously should cause clinical dermatologists to suspect the possibility of COVID-19 infection, especially in patients with fever and cough.
Assuntos
Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Síndrome Respiratória Aguda Grave/epidemiologia , Dermatopatias Virais/epidemiologia , Dermatopatias Virais/patologia , Adolescente , Fatores Etários , Biópsia por Agulha , COVID-19 , Estudos de Coortes , Comorbidade , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/terapia , DNA Viral/análise , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Incidência , Itália/epidemiologia , Masculino , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/terapia , Reação em Cadeia da Polimerase/métodos , Estudos Retrospectivos , Medição de Risco , Síndrome Respiratória Aguda Grave/diagnóstico , Índice de Gravidade de Doença , Fatores Sexuais , Dermatopatias Virais/terapia , Adulto JovemRESUMO
Mutations in the gelsolin protein are responsible for a rare conformational disease known as AGel amyloidosis. Four of these mutations are hosted by the second domain of the protein (G2): D187N/Y, G167R and N184K. The impact of the latter has been so far evaluated only by studies on the isolated G2. Here we report the characterization of full-length gelsolin carrying the N184K mutation and compare the findings with those obtained on the wild type and the other variants. The crystallographic structure of the N184K variant in the Ca2+-free conformation shows remarkable similarities with the wild type protein. Only minimal local rearrangements can be observed and the mutant is as efficient as the wild type in severing filamentous actin. However, the thermal stability of the pathological variant is compromised in the Ca2+-free conditions. These data suggest that the N to K substitution causes a local disruption of the H-bond network in the core of the G2 domain. Such a subtle rearrangement of the connections does not lead to significant conformational changes but severely affects the stability of the protein.
Assuntos
Amiloide/química , Gelsolina/química , Simulação de Dinâmica Molecular , Mutação de Sentido Incorreto , Amiloide/genética , Amiloide/metabolismo , Cálcio/metabolismo , Gelsolina/genética , Gelsolina/metabolismo , Humanos , Ligação de Hidrogênio , Domínios Proteicos , Estabilidade ProteicaRESUMO
The second domain of gelsolin (G2) hosts mutations responsible for a hereditary form of amyloidosis. The active form of gelsolin is Ca2+-bound; it is also a dynamic protein, hence structural biologists often rely on the study of the isolated G2. However, the wild type G2 structure that have been used so far in comparative studies is bound to a crystallographic Cd2+, in lieu of the physiological calcium. Here, we report the wild type structure of G2 in complex with Ca2+ highlighting subtle ion-dependent differences. Previous findings on different G2 mutations are also briefly revised in light of these results.
Assuntos
Cálcio/metabolismo , Gelsolina/química , Gelsolina/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Íons , Modelos Moleculares , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Mutação/genética , Ligação Proteica , Domínios ProteicosAssuntos
Amiloide/química , Amiloide/genética , Amiloidose/genética , Gelsolina/química , Gelsolina/genética , Mutação Puntual , Substituição de Aminoácidos , Amiloide/metabolismo , Amiloidose/metabolismo , Feminino , Gelsolina/metabolismo , Humanos , Masculino , Domínios Proteicos , Estabilidade ProteicaRESUMO
Inhibitors of Apoptosis Proteins (IAPs) are conserved E3-ligases that ubiquitylate substrates to prevent apoptosis and activate the NF-kB survival pathway, often deregulated in cancer. IAPs-mediated regulation of NF-kB signaling is based on the formation of protein complexes by their type-I BIR domains. The XIAP-BIR1 domain dimerizes to bind two TAB1 monomers, leading to downstream NF-kB activation. Thus, impairment of XIAP-BIR1 dimerization could represent a novel strategy to hamper cell survival in cancer. To this aim, we previously reported NF023 as a potential inhibitor of XIAP-BIR1 dimerization. Here we present a thorough analysis of NF023 binding to XIAP-BIR1 through biochemical, biophysical and structural data. The results obtained indicate that XIAP-BIR1 dimerization interface is involved in NF023 binding, and that NF023 overall symmetry and the chemical features of its central moiety are essential for an efficient interaction with the protein. Such strategy provides original hints for the development of novel BIR1-specific compounds as pro-apoptotic agents.