RESUMO
It is very popular to fuse a protein drug or drug candidate to the Fc domain of immunoglobulin G (IgG) in order to prolong the in vivo half-life. In this study, we have designed, prepared, and tested an Fc-fused thermostable cocaine esterase (CocE) mutant (known as E196-301, with the T172R/G173Q/L196C/I301C substitutions on CocE) expressed in E. coli. As expected, Fc-fusion does not affect the in vitro enzyme activity and thermal stability of the enzyme and that Fc-E196-301 can favorably bind FcRn with Kd = 386 ± 35 nM. However, Fc-fusion does not prolong the in vivo half-life of E196-301 at all; Fc-E196-301 and E196-301 have essentially the same PK profile (t1/2 = 0.4 ± 0.1 h) in rats. This is the first time demonstrating that Fc-fusion does not prolong in vivo half-life of a protein. This finding is consistent with the mechanistic understanding that E196-301 and Fc-E196-301 are all degraded primarily through rapid proteolysis in the body. The Fc fusion cannot protect E196-301 from the proteolysis in the body. Nevertheless, it has been demonstrated that PEGylation can effectively protect E196-301, as the PEGylated E196-301, i.e., PEG-E196-301, has a significantly prolonged in vivo half-life. It has also been demonstrated that both E196-301 and PEG-E196-301 have dose-dependent in vivo half-lives (e.g., 19.9 ± 6.4 h for the elimination t1/2 of 30 mg/kg PEG-E196-301), as the endogenous proteolytic enzymes responsible for proteolysis of E196-301 (PEGylated or not) are nearly saturated by the high plasma concentration produced by a high dose of E196-301 or PEG-E196-301.
Assuntos
Hidrolases de Éster Carboxílico/química , Estabilidade Enzimática/efeitos dos fármacos , Polietilenoglicóis/química , Animais , Proteínas de Bactérias , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/farmacocinética , Desenho de Fármacos , Escherichia coli/genética , Meia-Vida , Fragmentos Fc das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/farmacologia , Imunoglobulina G/imunologia , Proteínas Mutantes/química , Proteínas Mutantes/farmacocinética , Polietilenoglicóis/farmacologia , Proteólise/efeitos dos fármacos , RatosRESUMO
BACKGROUND Lupus nephritis is one of the most serious complications of systemic lupus erythematosus (SLE) and is associated with patient mortality. This study aimed to investigate the proteomic profiles of the glomerulus in the NZB/W F1 hybrid mouse model of mild and severe lupus nephritis using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) combined with matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF-MS). MATERIAL AND METHODS Female NZB/WF1 mice (n=60) at 28 weeks of age were divided into the mild proteinuria group (+1), the moderate proteinuria group (+2), and the severe proteinuria group (+3) using paper strip urine testing, and then later divided into a mild (≤1+) and severe (≥3+) proteinuria group to allow comparison of upregulation and down-regulation of proteins between the two groups. Renal glomeruli were isolated following renal perfusion with magnetic beads. Protein expression was determined by Western blot, immunohistochemistry, 2D-DIGE, and MALDI-TOF-MS. RESULTS A total of 56 differentially expressed proteins were identified from 133 protein spots, of which 18 were upregulated and 23 were down-regulated between groups 1 and 2. Expression of the proteins Ras-related GTP-binding protein B (RRAGB), serine/threonine-protein kinase 1 (SMG1), angiopoietin 2 (ANGP2), methylmalonate semialdehyde (MMSA), and ATP beta chain (ATPB) were identified by Western blot and SMG1, ANGP2, and MMSA were identified by immunohistochemistry. CONCLUSIONS In a mouse model of lupus nephritis, expression of SMG1, MMSA, and ATPB were down-regulated, and RRAGB and ANGP2 were upregulated.
Assuntos
Glomérulos Renais/metabolismo , Nefrite Lúpica/metabolismo , Proteômica/métodos , Angiopoietina-2/análise , Angiopoietina-2/metabolismo , Animais , Western Blotting , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica/métodos , Imuno-Histoquímica , Rim/metabolismo , Nefropatias , Lúpus Eritematoso Sistêmico/metabolismo , Nefrite Lúpica/fisiopatologia , Metilmalonato-Semialdeído Desidrogenase (Acilante)/análise , Metilmalonato-Semialdeído Desidrogenase (Acilante)/metabolismo , Camundongos , Camundongos Endogâmicos NZB , Proteínas Serina-Treonina Quinases/análise , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas/metabolismo , Proteinúria/metabolismo , Transcriptoma/genéticaRESUMO
Cocaine abuse is a world-wide public health and social problem without a US Food and Drug Administration-approved medication. An ideal anticocaine medication would accelerate cocaine metabolism, producing biologically inactive metabolites by administration of an efficient cocaine-specific exogenous enzyme. Our recent studies have led to the discovery of the desirable, highly efficient cocaine hydrolases (CocHs) that can efficiently detoxify and inactivate cocaine without affecting normal functions of the CNS. Preclinical and clinical data have demonstrated that these CocHs are safe for use in humans and are effective for accelerating cocaine metabolism. However, the actual therapeutic use of a CocH in cocaine addiction treatment is limited by its short biological half-life (e.g., 8 h or shorter in rats). Here we demonstrate a novel CocH form, a catalytic antibody analog, which is a fragment crystallizable (Fc)-fused CocH dimer (CocH-Fc) constructed by using CocH to replace the Fab region of human IgG1. The CocH-Fc not only has a high catalytic efficiency against cocaine but also, like an antibody, has a considerably longer biological half-life (e.g., â¼107 h in rats). A single dose of CocH-Fc was able to accelerate cocaine metabolism in rats even after 20 d and thus block cocaine-induced hyperactivity and toxicity for a long period. Given the general observation that the biological half-life of a protein drug is significantly longer in humans than in rodents, the CocH-Fc reported in this study could allow dosing once every 2-4 wk, or longer, for treatment of cocaine addiction in humans.
Assuntos
Hidrolases de Éster Carboxílico/administração & dosagem , Hidrolases de Éster Carboxílico/uso terapêutico , Transtornos Relacionados ao Uso de Cocaína/tratamento farmacológico , Animais , Biocatálise , Hidrolases de Éster Carboxílico/química , Hidrolases de Éster Carboxílico/toxicidade , Cocaína/metabolismo , Humanos , Hidrólise , Camundongos , Modelos Moleculares , Ratos Sprague-Dawley , Receptores Fc/metabolismo , Fatores de TempoRESUMO
Mouse butyrylcholinesterase (mBChE) and an mBChE-based cocaine hydrolase (mCocH, i.e. the A¹99S/S²²7A/S²87G/A³²8W/Y³³²G mutant) have been characterized for their catalytic activities against cocaine, i.e. naturally occurring (-)-cocaine, in comparison with the corresponding human BChE (hBChE) and an hBChE-based cocaine hydrolase (hCocH, i.e. the A¹99S/F²²7A/S²87G/A³²8W/Y³³²G mutant). It has been demonstrated that mCocH and hCocH have improved the catalytic efficiency of mBChE and hBChE against (-)-cocaine by ~8- and ~2000-fold respectively, although the catalytic efficiencies of mCocH and hCocH against other substrates, including acetylcholine (ACh) and butyrylthiocholine (BTC), are close to those of the corresponding wild-type enzymes mBChE and hBChE. According to the kinetic data, the catalytic efficiency (k(cat)/K(M)) of mBChE against (-)-cocaine is comparable with that of hBChE, but the catalytic efficiency of mCocH against (-)-cocaine is remarkably lower than that of hCocH by ~250-fold. The remarkable difference in the catalytic activity between mCocH and hCocH is consistent with the difference between the enzyme-(-)-cocaine binding modes obtained from molecular modelling. Further, both mBChE and hBChE demonstrated substrate activation for all of the examined substrates [(-)-cocaine, ACh and BTC] at high concentrations, whereas both mCocH and hCocH showed substrate inhibition for all three substrates at high concentrations. The amino-acid mutations have remarkably converted substrate activation of the enzymes into substrate inhibition, implying that the rate-determining step of the reaction in mCocH and hCocH might be different from that in mBChE and hBChE.
Assuntos
Hidrolases de Éster Carboxílico/metabolismo , Cocaína/metabolismo , Modelos Moleculares , Acetilcolina/química , Acetilcolina/metabolismo , Substituição de Aminoácidos , Animais , Sítios de Ligação , Biocatálise , Butirilcolinesterase/química , Butirilcolinesterase/genética , Butirilcolinesterase/metabolismo , Butiriltiocolina/química , Butiriltiocolina/metabolismo , Hidrolases de Éster Carboxílico/química , Hidrolases de Éster Carboxílico/genética , Cocaína/química , Ativação Enzimática , Humanos , Cinética , Camundongos , Simulação de Dinâmica Molecular , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Conformação Proteica , Engenharia de Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Especificidade por SubstratoRESUMO
Cocaine is a widely abused drug without an FDA (Food and Drug Administration)-approved medication. It has been recognized that an ideal anti-cocaine medication would accelerate cocaine metabolism producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway, i.e. human BChE (butyrylcholinesterase)-catalysed hydrolysis. However, the native human BChE has a low catalytic activity against cocaine. We recently designed and discovered a BChE mutant (A199S/F227A/S287G/A328W/Y332G) with a high catalytic activity (kcat=5700 min-1, Km=3.1 µM) specifically for cocaine, and the mutant was proven effective in protecting mice from acute cocaine toxicity of a lethal dose of cocaine (180 mg/kg of body weight, LD100). Further characterization in animal models requires establishment of a high-efficiency stable cell line for the BChE mutant production at a relatively larger scale. It has been extremely challenging to develop a high-efficiency stable cell line expressing BChE or its mutant. In the present study, we successfully developed a stable cell line efficiently expressing the BChE mutant by using a lentivirus-based repeated-transduction method. The scaled-up protein production enabled us to determine for the first time the in vivo catalytic activity and the biological half-life of this high-activity mutant of human BChE in accelerating cocaine clearance. In particular, it has been demonstrated that the BChE mutant (administered to mice 1 min prior to cocaine) can quickly metabolize cocaine and completely eliminate cocaine-induced hyperactivity in rodents, implying that the BChE mutant may be developed as a promising therapeutic agent for cocaine abuse treatment.
Assuntos
Butirilcolinesterase/metabolismo , Cocaína/metabolismo , Engenharia de Proteínas/métodos , Animais , Butirilcolinesterase/genética , Células CHO , Linhagem Celular , Transtornos Relacionados ao Uso de Cocaína , Cricetinae , Feminino , Humanos , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Ratos , Ratos Sprague-DawleyRESUMO
TIGIT is mainly expressed on T cells and is an inhibitory checkpoint receptor that binds to its ligand PVR in the tumor microenvironment. Anti-TIGIT monoclonal antibodies (mAbs) such as Ociperlimab and Tiragolumab block the TIGIT-PVR interaction and are in clinical development. However, the molecular blockade mechanism of these mAbs remains elusive. Here, we report the crystal structures of TIGIT in complex with Ociperlimab_Fab and Tiragolumab_Fab revealing that both mAbs bind TIGIT with a large steric clash with PVR. Furthermore, several critical epitopic residues are identified. Interestingly, the binding affinity of Ociperlimab toward TIGIT increases approximately 17-fold when lowering the pH from 7.4 to 6.0. Our structure shows a strong electrostatic interaction between ASP103HCDR3 and HIS76TIGIT explaining the pH-responsive mechanism of Ociperlimab. In contrast, Tiragolumab does not show an acidic pH-dependent binding enhancement. Our results provide valuable information that could help to improve the efficacy of therapeutic antibodies for cancer treatment.
Assuntos
Modelos Moleculares , Ligação Proteica , Receptores Imunológicos , Concentração de Íons de Hidrogênio , Humanos , Receptores Imunológicos/metabolismo , Receptores Imunológicos/química , Cristalografia por Raios X , Anticorpos Monoclonais/química , Sítios de Ligação , Anticorpos Monoclonais Humanizados/química , Anticorpos Monoclonais Humanizados/farmacologia , Anticorpos Monoclonais Humanizados/imunologiaRESUMO
Causal effect estimation of individual heterogeneity is a core issue in the field of causal inference, and its application in medicine poses an active and challenging problem. In high-risk decision-making domain such as healthcare, inappropriate treatments can have serious negative impacts on patients. Recently, machine learning-based methods have been proposed to improve the accuracy of causal effect estimation results. However, many of these methods concentrate on estimating causal effects of continuous outcome variables under binary intervention conditions, and give less consideration to multivariate intervention conditions or discrete outcome variables, thus limiting their scope of application. To tackle this issue, we combine the double machine learning framework with Light Gradient Boosting Machine (LightGBM) and propose a double LightGBM model. This model can estimate binary causal effects more accurately and in less time. Two cyclic structures were added to the model. Data correction method was introduced and improved to transform discrete outcome variables into continuous outcome variables. Multivariate Cyclic Double LightGBM model (MCD-LightGBM) was proposed to intelligently estimate multivariate treatment effects. A visual human-computer interaction system for heterogeneous causal effect estimation was designed, which can be applied to different types of data. This paper reports that the system improved the Logarithm of the Minimum Angle of Resolution (LogMAR) of visual acuity change after Vascular Endothelial Growth Factor (anti-VEGF) treatment in patients with diabetic macular degeneration. The improvement was observed in two clinical problems, from 0.05 to 0.33, and the readmission rate of diabetic patients after cure was reduced from 48.4% to 10.5%. The results above demonstrate the potential of the proposed system in predicting heterogeneous clinical drug treatment effects.
RESUMO
Cocaine is one of the most addictive drugs, and there is still no FDA (Food and Drug Administration)-approved medication specific for cocaine abuse. A promising therapeutic strategy is to accelerate cocaine metabolism, producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway, i.e. cocaine hydrolysis catalyzed by butyrylcholinesterase (BChE) in plasma. However, the native BChE has a low catalytic efficiency against the abused cocaine, i.e. (-)-cocaine. Our recently designed and discovered A199S/F227A/S287G/A328W/Y332G mutant and other mutants of human BChE have a considerably improved catalytic efficiency against (-)-cocaine. In the present study, we carried out both computational modeling and experimental kinetic analysis on the catalytic activities of these promising new BChE mutants against other known substrates, including neurotransmitter acetylcholine (ACh), acetylthiocholine (ATC), butyrylthiocholine (BTC), and (+)-cocaine, in comparison with the corresponding catalytic activity against (-)-cocaine. Both the computational modeling and kinetic analysis have consistently revealed that all the examined amino acid mutations only considerably improve the catalytic efficiency of human BChE against (-)-cocaine, without significantly improving the catalytic efficiency of the enzyme against any of the other substrates examined. In particular, all the examined BChE mutants have a slightly lower catalytic efficiency against neurotransmitter ACh compared to the wild-type BChE. This observation gives us confidence in developing an anti-cocaine enzyme therapy by using one of these BChE mutants, particularly the A199S/F227A/S287G/A328W/Y332G mutant.
Assuntos
Butirilcolinesterase/genética , Butirilcolinesterase/metabolismo , Acetilcolina/química , Acetilcolina/metabolismo , Acetiltiocolina/química , Acetiltiocolina/metabolismo , Biocatálise , Butirilcolinesterase/química , Butiriltiocolina/química , Butiriltiocolina/metabolismo , Cocaína/química , Cocaína/metabolismo , Ativação Enzimática , Humanos , Cinética , Modelos Moleculares , Mutação , Especificidade por SubstratoRESUMO
OBJECTIVE: To establish Chinese medicine diagnosis and treatment standard procedure for patients with HIV associated pruritus. METHODS: A Chinese medicine diagnosis and treatment standard procedure for patients with HIV associated pruritus was established by literature retrieval and peer review. Two questionnaires were carried out to investigate the confirmation and advice of in-group specialists to key points of the draft including diagnosis, treatment and nursing. Then the procedures were revised accordingly. RESULTS: The recovery rate of complete questionnaires in the 1st survey was 96%. Specialists confirmed more on case history and physical examinations, syndrome differentiation of three syndrome types, treatment of blood deficiency wind dryness syndrome (BDWDS) and nursing. They held different opinions on the outlines, auxiliary examinations, treatment of blood heat induced wind evil syndrome (BHWES) and wind cold and dampness accumulation syndrome (WCDAS), of which the coefficient of variations (CVs) was within 0.1603 -0.2473. The procedures were revised and the 2nd survey was launched. The recovery rate of complete questionnaires in the 2nd survey was 100%. Specialists confirmed more on case history and physical examinations, diagnostic criteria, syndrome differentiation of BDWDS and WCDAS, and treatment of BDWDS, of which CVs was 0. All indicated high agreement and good compliance. The CVs of other items were within 0.0638-0.1439, less than those of the 1st survey. The consistency of experts' opinions were somewhat improved. The contribution by one single item showed less difference in assessing the overall results in the two surveys. A new revision of the procedure was preliminarily established according to results of two surveys. CONCLUSIONS: Experts' activeness, concentration, and coordination were good in the two surveys. They had reached consensus in key points of the draft including diagnosis, treatment, and nursing.
Assuntos
Consenso , Infecções por HIV/terapia , Medicina Tradicional Chinesa/métodos , Prurido/terapia , Inquéritos e Questionários , Infecções por HIV/complicações , Humanos , Prurido/etiologiaRESUMO
The pathogenesis of acquired immune deficiency syndrome-associated recurrent oral ulcerations (AIDS-ROU) remained obscure and these was no specific treatment for it. Syndrome differentiation in traditional Chinese medicine (TCM) focus on integral regulation and has an advantage of the disease that etiology and pathogenesis remain obscure. A draft of Chinese medicine diagnosis and treatment standard procedure for AIDS-ROU was established by literature retrieval and peer review. Two questionnaires were carried out to investigate the confirmation and advice of in-group specialist to key points of the draft including diagnosis, treatment and nursing. Then the procedures were revised accordingly. The preliminary results showed the recovery rate of complete questionnaires in the 1st survey was 96%. Specialists confirmed more on outline, case history and physical examinations, syndrome differentiation of hyperactivity of fire due to Yin deficiency syndrome (HFYDS), treatment of heat accumulated in heart and spleen syndrome (HAHSS) and HFYDS, treatment of western medicine and nursing. They held different opinions on incidence, treatment of deficiency of spleen-QI and stomach-QI syndrome (DSSS) and criterion of therapeutical evaluation. Cronbach coefficient alpha (CCA) was 0.998 and split-half reliability R was 0.91. Recovery rate of complete questionnaires in 2nd survey was 100%. Specialists confirmed more on outline, etiology and pathogenesis, case history and physical examination, auxiliary examination, diagnostic criteria, syndrome differentiation and treatment of HAHSS and HFYDS. They held different opinions on syndrome differentiation and treatment of intermingled cold and heat syndrome and DSSS, nursing and the other therapies. CCA was 0.428 and split-half reliability R was 0.96. Coefficient of variations of the 2nd survey were less than those of the 1st survey, which mean coordination was improved. Each single item in two surveys contributed less difference in overall results according to weight coefficients. A new revision of the procedure was preliminarily established according to results of two surveys. Experts'activeness, concentration and coordination were good in two surveys. They had reached consensus in key points of the draft including diagnosis, treatment and nursing on the whole.
Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Medicina Tradicional Chinesa/métodos , Úlceras Orais/diagnóstico , Úlceras Orais/terapia , Inquéritos e Questionários , Consenso , Feminino , Humanos , Masculino , Medicina Tradicional Chinesa/normas , Úlceras Orais/complicações , Recidiva , Padrões de ReferênciaRESUMO
OBJECTIVE: To norm the behavior of AIDS cough in traditional Chinese medicine diagnosis and treatment and improve the clinical level of cough treatment for HIV/AIDS, and build AIDS cough diagnosis and treatment procedures in traditional Chinese medicine. METHOD: Combined with clinical practice,to formulate questionnaire on AIDS cough in traditional Chinese medicine diagnosis and treatment by both English and Chinese literature research to expertise consultation and verify the results of the questionnaires on the statistics using the Delphi method. RESULT: Questionnaire contents consist of overview, pathogeny, diagnosis standard, dialectical medication (phlegm heat resistance pulmonary lung and kidney Yin deficiency lung spleen-deficiency), treating spleen-deficiency (lung), moxibustion treatment and aftercare care and diet and mental, average (2.93-3.00), full mark rate (93.10%-100%) ranks average (9.91-10.67) and (287.50-309.50) of which are the most high value, and the variation coefficient is 0.00, the Kendall coefficient (Kendalls W) is 0.049 which is statistical significance, the questionnaire reliability value of alpha was 0.788. CONCLUSION: Preliminary standarded concept, etiology and pathogenesis, diagnosis and syndrome differentiation treatment of AIDS cough, basically recognised by the experts in this field, and laid the foundation of traditional Chinese medicine diagnosis and treatment on develop the AIDS cough specifications.
Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Tosse/diagnóstico , Tosse/terapia , Medicina Tradicional Chinesa/métodos , Inquéritos e Questionários , Tosse/complicações , Humanos , Medicina Tradicional Chinesa/normas , Padrões de ReferênciaRESUMO
A combined computational and experimental study has been carried out to explore and test a quantitative correlation relationship between the relative catalytic efficiency (RCE) of human butyrylcholinesrase (BChE) mutant-catalyzed hydrolysis of substrate (-)-cocaine and the total hydrogen bonding energy (tHBE) of the carbonyl oxygen of the substrate with the oxyanion hole of the enzyme in the modeled transition-state structure (TS1), demonstrating a satisfactory linear correlation relationship between ln(RCE) and tHBE. The satisfactory correlation relationship has led us to computationally predict and experimentally confirm new human BChE mutants that have a further improved catalytic activity against (-)-cocaine, including the most active one (the A199S/F227S/S287G/A328W/Y332G mutant) with a 2790-fold improved catalytic efficiency (kcat/KM = 2.5 × 109 min-1 M-1) compared to the wild-type human BChE. Compared to the reference mutant (the A199S/S287G/A328W/Y332G mutant) tested in the reported clinical development of an enzyme therapy for cocaine dependence treatment, this new mutant (with a newly predicted additional F227S mutation) has an improved catalytic efficiency against (-)-cocaine by â¼2.6-fold. The good agreement between the computational and experimental ln(RCE) values suggests that the obtained correlation relationship is robust for computational prediction. A similar correlation relationship could also be explored in studying BChE or other serine hydrolases/esterases with an oxyanion hole stabilizing the carbonyl oxygen in the rate-determining reaction step of the enzymatic hydrolysis of other substrates.
Assuntos
Butirilcolinesterase , Cocaína , Humanos , Butirilcolinesterase/genética , Butirilcolinesterase/química , Catálise , Cocaína/química , Ligação de Hidrogênio , Hidrólise , Modelos Moleculares , OxigênioRESUMO
Aspartic acid (Asp) isomerization is a spontaneous non-enzymatic post-translation modification causing a change in the structure of the protein backbone, which is commonly observed in therapeutic antibodies during manufacturing and storage. The Asps in Asp-Gly (DG), Asp-Ser (DS), and Asp-Thr (DT) motifs in the structurally flexible regions, such as complementarity-determining regions (CDRs) in antibodies, are often found to have high rate of isomerization, and they are considered "hot spots" in antibodies. In contrast, the Asp-His (DH) motif is usually considered a silent spot with low isomerization propensity. However, in monoclonal antibody mAb-a, the isomerization rate of an Asp residue, Asp55, in the aspartic acid-histidine-lysine (DHK) motif present in CDRH2 was found to be unexpectedly high. By determining the conformation of DHK motif in the crystal structure of mAb-a, we found that the Cgamma of the Asp side chain carbonyl group and the back bone amide nitrogen of successor His were in proximal contact, which facilitates the formation of succinimide intermediate, and the +2 Lys played an important role in stabilizing such conformation. The contributing roles of the His and Lys residues in DHK motif were also verified using a series of synthetic peptides. This study identified a novel Asp isomerization hot spot, DHK, and the structural-based molecular mechanism was revealed. When 20% Asp55 isomerization in this DHK motif occurred in mAb-a, antigen binding activity reduced to 54%, but the pharmacokinetics in rat was not affected significantly. Although Asp isomerization of DHK motif in CDR does not appear to have a negative impact on PK, DHK motifs in the CDRs of antibody therapeutics should be removed, considering the high propensity of isomerization and impact on antibody activity and stability.
Assuntos
Ácido Aspártico , Peptídeos , Animais , Ratos , Isomerismo , Ácido Aspártico/química , Peptídeos/química , Regiões Determinantes de Complementaridade/química , Anticorpos Monoclonais/químicaRESUMO
TIGIT (T-cell immunoglobulin and ITIM domain) has emerged as a promising target in cancer immunotherapy. It is an immune "checkpoint" inhibitor primarily expressed on activated T cells, NK cells and Tregs. Engagement of TIGIT to its ligands PVR and PVR-L2 leads to inhibitory signaling in T cells, promoting functional exhaustion of tumor-infiltrating T lymphocytes. Here, we described the pre-clinical characterization of Ociperlimab (BGB-A1217), a novel humanized IgG1 anti-TIGIT antibody (mAb), and systemically evaluated the contribution of Fc functions in the TIGIT mAb-mediated anti-tumor activities. BGB-A1217 binds to the extracellular domain of human TIGIT with high affinity (KD = 0.135 nM) and specificity, and efficiently blocks the interaction between TIGIT and its ligands PVR or PVR-L2. Cell-based assays show that BGB-A1217 significantly enhances T-cell functions. In addition, BGB-A1217 induces antibody dependent cellular cytotoxicity (ADCC) against Treg cells, activates NK cells and monocytes, and removes TIGIT from T cell surfaces in an Fc-dependent manner, In vivo, BGB-A1217, either alone or in combination with an anti-PD-1 mAb elicits strong immune responses and potent anti-tumor efficacy in pre-clinical models. Moreover, the Fc effector function is critical for the anti-tumor activity of BGB-A1217 in a syngeneic human TIGIT-knock-in mouse model. The observed anti-tumor efficacy is associated with a pharmacodynamic change of TIGIT down-regulation and Treg reduction. These data support the selection of BGB-A1217 with an effector function competent Fc region for clinical development for the treatment of human cancers.
Assuntos
Neoplasias , Receptores Imunológicos , Animais , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Inibidores de Checkpoint Imunológico , Imunidade , Ligantes , Camundongos , Neoplasias/tratamento farmacológico , Receptores Imunológicos/metabolismoRESUMO
Cocaine is a widely abused drug without a U.S. Food and Drug Administration-approved medication. There is a recognized, promising anticocaine medication to accelerate cocaine metabolism, producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway [i.e., cocaine hydrolysis catalyzed by butyrylcholinesterase (BChE) in plasma]. An ideal, therapeutically valuable mutant of human BChE should have not only a significantly improved catalytic activity against (-)-cocaine but also certain selectivity for (-)-cocaine over neurotransmitter acetylcholine (ACh), such that one would not expect systemic administration of the BChE mutant to interrupt cholinergic transmission. The present study accounting for the mutation-caused changes of the catalytic activities of BChE against both (-)-cocaine and ACh by means of molecular modeling and site-directed mutagenesis has led to identification of three BChE mutants that have not only a considerably improved catalytic efficiency against (-)-cocaine but also the desirable selectivity for (-)-cocaine over ACh. Two representative BChE mutants have been confirmed to be potent in actual protection of mice from acute toxicity (convulsion and lethality) of a lethal dose of cocaine (180 mg/kg). Pretreatment with the BChE mutant (i.e., 1 min before cocaine administration) dose-dependently protected mice against cocaine-induced convulsions and lethality. In particular, all mice pretreated with the mutant (e.g., 0.02 mg or more of A199S/F227A/S287G/A328W/E441D BChE) survived. The in vivo data reveal the primary factor (i.e., the relative catalytic efficiency), determining the efficacy in practical protection of mice from the acute cocaine toxicity and future direction for further improving the efficacy of the enzyme in the cocaine overdose treatment.
Assuntos
Butirilcolinesterase/metabolismo , Cocaína/farmacocinética , Inativação Metabólica , Acetilcolina/metabolismo , Animais , Butirilcolinesterase/genética , Cocaína/toxicidade , Humanos , Ligação de Hidrogênio , Masculino , Camundongos , Modelos Moleculares , Mutagênese Sítio-Dirigida , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
Background: The decline in the physical fitness of college students has become a serious social problem worldwide. Therefore, exploring the factors affecting the amount of exercise of college students is of great significance in improving college students' physique. According to the expectation value theory and previous studies, perceived exercise benefit and perceived severity of disease and weakness may have positive or negative impact on exercise behavior, and according to the self-efficacy theory, physical evaluation self-efficacy may be the most powerful motivational factors and it play a mediating role between other factors and exercise behavior. Therefore, this study was designed to determine the critical role of physical evaluation self-efficacy in the path of perceived exercise benefit and perceived severity of disease and weakness affecting the amount of exercise of college students. Methods: By means of Physical Fitness Health Belief of College Students Scale and Physical Activity Rating Scale (PARS-3), 801 undergraduate students were investigated in this study. Results: (1) When perceived exercise benefit, exercise self-efficacy, and severity of perceived disease and weakness predicted the amount of exercise separately, the first two have a positive effect on the amount of exercise, but the latter has no effect. However, when these three factors entered the regression equation at the same time, the perceived severity of disease and weakness had a negative effect on the amount of exercise. (2) The influence of physical evaluation self-efficacy on the college students' the amount of exercise was bigger than benefit of perceived exercise and the perceived severity of disease and weakness in both separated and simultaneous comparison conditions. (3) Physical evaluation self-efficacy completely mediated the positive effect of perceived exercise benefits on the amount of exercise and inhibited the negative effect of perceived severity of disease and weakness on the amount of exercise. Conclusion: Physical evaluation self-efficacy has a strong predictive power on the amount of exercise of college students. This was reflected in its ability to mediate the impact of expectation of exercise results and in its ability to suppress the adverse effects of concern about illness on exercise.
RESUMO
The AP2/ERF is a large protein family of transcription factors, playing an important role in signal transduction, plant growth, development, and response to various stresses. AP2/ERF super-family is identified and functionalized in a different plant but no comprehensive and systematic analysis in wheat (Triticum aestivum L.) has been reported. However, a genome-wide and functional analysis was performed and identified 322 TaAP2/ERF putative genes from the wheat genome. According to the phylogenetic and structural analysis, TaAP2/ERF genes were divided into 12 subfamilies (Ia, Ib, Ic, IIa, IIb, IIc, IIIa, IIIb, IIIc, IVa, IVb, and IVc). Furthermore, conserved motifs and introns/exons analysis revealed may lead to functional divergence within clades. Cis-Acting analysis indicated that many elements were involved in stress-related and plant development. Chromosomal location showed that 320 AP2/ERF genes were distributed among 21 chromosomes and 2 genes were present in a scaffold. Interspecies microsynteny analysis revealed that maximum orthologous between Arabidopsis, rice followed by wheat. Segment duplication events have contributed to the expansion of the AP2/ERF family and made this family larger than rice and Arabidopsis. Additionally, AP2/ERF genes were differentially expressed in wheat seedlings under the stress treatments of heat, salt, and drought, and expression profiles were verified by qRT-PCR. Remarkably, the RNA-seq data exposed that AP2/ERF gene family might play a vital role in stress-related. Taken together, our findings provided useful and helpful information to understand the molecular mechanism and evolution of the AP2/ERF gene family in wheat.
RESUMO
The present study was aimed to explore the correlation between the protein structure and catalytic efficiency of butyrylcholinesterase (BChE) mutants against (-)-cocaine by modeling the rate-determining transition state (TS1), i.e., the transition state for the first step of chemical reaction process, of (-)-cocaine hydrolysis catalyzed by various mutants of human BChE in comparison with the wild type. Molecular modeling of the TS1 structures revealed that mutations on certain nonactive site residues can indirectly affect the catalytic efficiency of the enzyme against (-)-cocaine through enhancing or weakening the overall hydrogen bonding between the carbonyl oxygen of (-)-cocaine benzoyl ester and the oxyanion hole of the enzyme. Computational insights and predictions were supported by the catalytic activity data obtained from wet experimental tests on the mutants of human BChE, including five new mutants reported for the first time. The BChE mutants with at least â¼1000-fold improved catalytic efficiency against (-)-cocaine compared to the wild-type BChE are all associated with the TS1 structures having stronger overall hydrogen bonding between the carbonyl oxygen of (-)-cocaine benzoyl ester and the oxyanion hole of the enzyme. The combined computational and experimental data demonstrate a reasonable correlation relationship between the hydrogen-bonding distances in the TS1 structure and the catalytic efficiency of the enzyme against (-)-cocaine.
Assuntos
Butirilcolinesterase/química , Butirilcolinesterase/metabolismo , Cocaína/metabolismo , Substituição de Aminoácidos , Butirilcolinesterase/genética , Domínio Catalítico/genética , Humanos , Ligação de Hidrogênio , Técnicas In Vitro , Cinética , Modelos Moleculares , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Engenharia de Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
Imbalances in the gut microbiota mediate the progression of neurodegenerative diseases such as Parkinson's disease (PD). Fecal microbiota transplantation (FMT) is currently being explored as a potential therapy for PD. The objective of this study was to assess the efficacy and safety of FMT on PD. Fifteen PD patients were included, 10 of them received FMT via colonoscopy (colonic FMT group) and 5 received FMT via nasal-jejunal tube (nasointestinal FMT group). The score of PSQI, HAMD, HAMA, PDQ-39, NMSQ and UPDRS-III significantly decreased after FMT treatment (all Pâ<â.05). Colonic FMT group showed significant improvement and longer maintenance of efficacy compared with nasointestinal FMT (Pâ=â.002). Two patients achieved self-satisfying outcomes that last for more than 24 months. However, nasointestinal FMT group had no significant therapeutic effect, although UPDRS-III score slightly reduced. There were no patients were satisfied with nasointestinal FMT for more than 3 months. Among 15 PD patients, there were 5 cases had adverse events (AEs), including diarrhea (2 cases), abdominal pain (2 cases) and flatulence (1 case). These AEs were mild and self-limiting. We conclude that FMT can relieve the motor and non-motor symptoms with acceptable safety in PD. Compared with nasointestinal FMT, colonic FMT seems better and preferable.
Assuntos
Transplante de Microbiota Fecal/estatística & dados numéricos , Doença de Parkinson/terapia , Idoso , Colonoscopia , Transplante de Microbiota Fecal/efeitos adversos , Transplante de Microbiota Fecal/métodos , Feminino , Humanos , Intubação Gastrointestinal , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Projetos Piloto , Adulto JovemRESUMO
A number of studies indicated that apoptosis, a specific type of programmed cell death, contributed to the loss of dopaminergic neurons during progression of Parkinson's disease (PD). Previously, the authors of the present study demonstrated that apoptosis of dopaminergic neurons was mainly achieved via the mitochondria-mediated apoptosis pathway, however, the precise molecular mechanisms remain to be elucidated. The present study aimed to determine whether mitofusin-2 (MFN2), a mitochondrial protein, participated in the apoptosis of dopaminergic neurons in a cellular model of PD induced by rotenone. The present study demonstrated that the expression of MFN2 was relatively stable following treatment with rotenone. Lentiviral knockdown and overexpression experiments for the first time, to the best of the authors knowledge, revealed that MFN2 prevented rotenone-induced cell death by amelioration of apoptosis. These results revealed a protective role of MFN2 against apoptosis in an in vitro model of PD and may be used to establish MFN2 as a potential therapeutic target for the treatment of this disease.