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1.
Am J Cardiol ; 177: 22-27, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35718549

RESUMO

The extent of intervention effects on carotid intima-media thickness (CIMT) can predict the degree of atherosclerotic cardiovascular risk-reduction. We hypothesized that regular lipoprotein apheresis over the course of 10 years might slow down progression of CIMT in patients with severe hypercholesterolemia. This case series describes 10 Caucasian patients (mean age 60 ± 9 years, 70% female, 80% statin intolerant) with a severe hypercholesterolemia phenotype treated with lipoprotein apheresis between 2005 and 2020 (mean duration, 10 ± 4 years). The median pretreatment low-density lipoprotein cholesterol (LDL-C) level was 214 mg/100 ml (95% confidence interval, 145 to 248), lipoprotein(a) (Lp[a]), 26 mg/100 ml (15 to 109; 40% with Lp(a)>60 mg/100 ml). Three patients were diagnosed with a monogenic cause. The baseline mean CIMT was 850 ± 170 µm, and maximum CIMT was 1,040 ± 220 µm across the age range of 46 to 70 years. Acute effects of lipoprotein apheresis determined as a difference before and immediately after the procedure were estimated as a median of 72 ± 8% and 75 ± 7% reduction in the LDL-C and Lp(a) levels, respectively. Using the imputed trajectories, period-specific on-treatment time-weighted averages for LDL-C and Lp(a) were 141 mg/100 ml (interquartile range, 89 to 152; 38% reduction from the baseline) and 24 mg/100 ml (interquartile range, 12 to 119; 19% reduction from baseline), respectively. The number of patients with CIMT above their "vascular age" decreased from 80% to 30% over the treatment course. In conclusion, an increase in CIMT seen with advanced age and severe hypercholesterolemia was halted with lipoprotein apheresis with an estimated annual rate of change in mean common CIMT of -4 µm/y and maximum CIMT of -3 µm/y.


Assuntos
Remoção de Componentes Sanguíneos , Inibidores de Hidroximetilglutaril-CoA Redutases , Hipercolesterolemia , Remoção de Componentes Sanguíneos/métodos , Espessura Intima-Media Carotídea , LDL-Colesterol , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipercolesterolemia/complicações , Hipercolesterolemia/terapia , Lipoproteína(a) , Masculino
2.
J Clin Lipidol ; 14(6): 818-824, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32978095

RESUMO

BACKGROUND: The previously published ODYSSEY ESCAPE trial demonstrated a significant reduction in the use of lipoprotein apheresis for heterozygous familial hypercholesterolemia (HeFH) patients when placed on alirocumab 150 mg every 2 weeks. In patients with HeFH who have consistently elevated levels of low-density lipoprotein cholesterol (LDL-C) despite maximally tolerated statin therapy, current lipid guidelines recommend apheresis. Although apheresis reduces LDL-C levels by 50%-75%, it must be repeated, as frequently as every 1-2 weeks. OBJECTIVE: To assess clinical experience with apheresis and alirocumab for patients in a real-world practice setting. METHODS: This retrospective review included patients from 5 apheresis centers who were treated with apheresis and had started alirocumab therapy. In addition to LDL-C levels, total cholesterol, high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglycerides, and particle numbers were evaluated if data were available. RESULTS: Eleven of the 25 (44%) patients discontinued apheresis completely after initiation of alirocumab therapy, having achieved LDL-C <70 mg/dL or >50% reduction from baseline levels. Among the 14 patients who remained on apheresis, seven decreased the frequency of apheresis sessions. No significant safety problems were reported. CONCLUSION: Alirocumab lowered LDL-C levels by an average of 55.5% in patients receiving apheresis for elevated LDL-C. Seventy-two percent of patients on alirocumab therapy discontinued or reduced the frequency of apheresis treatment. However, some patients continued to require apheresis due to elevated lipoprotein(a), extremely elevated LDL-C, or if alirocumab therapy was discontinued due to less than anticipated LDL-C reduction.


Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Remoção de Componentes Sanguíneos , Anticorpos Monoclonais Humanizados/uso terapêutico , Feminino , Humanos , Hipercolesterolemia/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
3.
PLoS One ; 14(12): e0226320, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31846475

RESUMO

BACKGROUND: Genital herpes simplex infection affects more than 500 million people worldwide. We have previously shown that COR-1, a therapeutic HSV-2 polynucleotide vaccine candidate, is safe and well tolerated in healthy subjects. OBJECTIVE: Here, we present a single center double-blind placebo-controlled, randomized phase I/IIa trial of COR-1 in HSV-2 positive subjects in which we assessed safety and tolerability as primary endpoints, and immunogenicity and therapeutic efficacy as exploratory endpoints. METHODS: Forty-four HSV-2+ subjects confirmed by positive serology or pathology, and positive qPCR during baseline shedding, with a recurrent genital HSV-2 history of at least 12 months including three to nine reported lesions in 12 months prior to screening, aged 18 to 50 years females and males with given written informed consent, were randomized into two groups. Three immunizations at 4-week intervals and one booster immunization at 6 months, each of 1 mg COR-1 DNA or placebo, were administered intradermally as two injections of 500 µg each to either one forearm or both forearms. RESULTS: No serious adverse events, life-threatening events or deaths occurred throughout the study. As expected, HSV-2 infected subjects displayed gD2-specific antibody titers prior to immunization. COR-1 was associated with a reduction in viral shedding after booster administration compared with baseline. CONCLUSIONS: This study confirms the previously demonstrated safety of COR-1 in humans and indicates a potential for use of COR-1 as a therapy to reduce viral shedding in HSV-2 infected subjects.


Assuntos
Herpes Genital/prevenção & controle , Herpesvirus Humano 2/imunologia , Herpesvirus Humano 2/fisiologia , Imunoterapia/métodos , Polinucleotídeos/imunologia , Adolescente , Adulto , Formação de Célula em Célula , Surtos de Doenças/prevenção & controle , Método Duplo-Cego , Feminino , Herpes Genital/epidemiologia , Herpes Genital/imunologia , Humanos , Imunidade Celular/imunologia , Imunidade Humoral , Imunoterapia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Segurança , Vacinas Virais/imunologia , Eliminação de Partículas Virais , Adulto Jovem
4.
Br J Community Nurs ; 23(1): 14-19, 2018 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-29281909

RESUMO

Diabetes is a common long-term condition affecting many people many of whom require support with their insulin injections at home. These injections are often carried out by community nurses if individuals are unable to self-manage their condition. This paper describes a pilot project where health care support workers were trained to administer insulin at home for suitable patients. Four patients took part in the pilot study and two support workers were trained to give the insulin injections. The project was evaluated well by all those who took part. It freed up 80 hours of nursing time while also providing the support workers with an extended scope of practice and associated increased in job satisfaction. No untoward medication errors were reported as a result of this initiative. This project will now be rolled out to the wider nursing teams with a staggered approach to the delivery of the training to ensure there is not a detrimental effect on patient care.


Assuntos
Pessoal Técnico de Saúde , Enfermagem em Saúde Comunitária , Diabetes Mellitus Tipo 2/tratamento farmacológico , Insulina/administração & dosagem , Padrões de Prática em Enfermagem , Diabetes Mellitus Tipo 2/enfermagem , Humanos , Projetos Piloto , Medicina Estatal , Reino Unido
5.
J Immunother ; 40(2): 62-70, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28166181

RESUMO

We have previously shown that a novel DNA vaccine technology of codon optimization and the addition of ubiquitin sequences enhanced immunogenicity of a herpes simplex virus 2 polynucleotide vaccine in mice, and induced cell-mediated immunity when administered in humans at relatively low doses of naked DNA. We here show that a new polynucleotide vaccine using the same technology and encoding a fusion protein of the E6 and E7 oncogenes of high-risk human papillomavirus type 16 (HPV16) is immunogenic in mice. This vaccine induces long-lasting humoral and cell-mediated immunity and protects mice from establishment of HPV16-E7-expressing tumors. In addition, it suppresses growth of readily established tumors and shows enhanced efficacy when combined with immune checkpoint blockade targeted at PD-L1. This vaccine also facilitates rejection of HPV16-E7-expressing skin grafts that demonstrate epidermal hyperplasia with characteristics of cervical and vulvar intraepithelial neoplasia. Clinical studies evaluating the efficacy of this vaccine in patients with HPV16 premalignancies are planned.


Assuntos
Rejeição de Enxerto/imunologia , Papillomavirus Humano 16/imunologia , Infecções por Papillomavirus/imunologia , Vacinas contra Papillomavirus/imunologia , Neoplasias do Colo do Útero/prevenção & controle , Animais , Anticorpos Monoclonais/administração & dosagem , Antígeno B7-H1/imunologia , Processos de Crescimento Celular , Feminino , Papillomavirus Humano 16/genética , Humanos , Imunidade Celular , Imunidade Humoral , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Oncogênicas Virais/genética , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Infecções por Papillomavirus/complicações , Proteínas Repressoras/genética , Pele/metabolismo , Transplante de Pele , Neoplasias do Colo do Útero/etiologia , Vacinação , Vacinas de DNA
6.
Hum Vaccin Immunother ; 12(12): 3079-3088, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27580249

RESUMO

This paper describes a single site, open-label Phase I clinical trial evaluating the safety, tolerability and immunogenicity in healthy volunteers of a herpes simplex polynucleotide vaccine that has previously been shown to enhance immunogenicity and protect against lethal herpes simplex virus type 2 (HSV-2) challenge in mice. Five escalating doses of the vaccine, COR-1, were given by intradermal injection to HSV-1 and 2 seronegative healthy individuals. COR-1 was found to be safe and well-tolerated; the only vaccine-related adverse events were mild. While vaccine-induced antibody responses were not detectable, cell-mediated immune responses to HSV-specific peptide groups were identified in 19 of the 20 subjects who completed the study, and local inflammation at the immunisation site was observed. This study indicates COR-1 has potential to be used as a therapeutic vaccine for HSV-2 infection.


Assuntos
Vacinas contra o Vírus do Herpes Simples/efeitos adversos , Vacinas contra o Vírus do Herpes Simples/imunologia , Herpes Simples/prevenção & controle , Herpesvirus Humano 2/imunologia , Vacinas de DNA/efeitos adversos , Vacinas de DNA/imunologia , Adulto , Anticorpos Antivirais/sangue , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Feminino , Vacinas contra o Vírus do Herpes Simples/administração & dosagem , Humanos , Injeções Intradérmicas , Leucócitos Mononucleares/imunologia , Masculino , Vacinas de DNA/administração & dosagem , Adulto Jovem
7.
J Clin Apher ; 31(4): 388-92, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26126949

RESUMO

BACKGROUND: Plasma galectin-3 (Gal-3) is elevated in, and drives, diverse systemic inflammatory disorders, including cancer, cardiovascular diseases, and diabetes. Circulating Gal-3 promotes tumorigenesis and metastasis, as well as fibrotic remodeling, and is a promising therapeutic target. Apheresis has proven utility in reducing circulating disease-promoting substances, exemplified by the success of lipoprotein apheresis (LA) in abrogating cardiovascular disease progression in drug-refractory hypercholesterolemia patients. We compared the clinical utility of two FDA-approved LA systems in reducing plasma Gal-3 in humans. METHODS: Plasma Gal-3 levels were assessed by ELISA in blinded samples drawn pre- and post-apheresis from hypercholesterolemia patients (n = 10/group) undergoing therapeutic LA using either a heparin-induced extracorporeal LDL precipitation (HELP) or dextran sulfate-adsorption (DSA) system. RESULTS: Mean baseline plasma Gal-3 concentrations (±SD) were 14.3 ± 5.1 (range 6.6-22.8) and 14.5 ± 2.8 (range 10.6-19.8) ng/mL in the HELP and DSA groups, respectively. Post-apheresis Gal-3 levels were respectively reduced by 19.4% and 22.7% in the HELP (P = 0.0094) and DSA (P = 0.0027) systems (paired t-tests); the difference between devices was insignificant (P = 0.5288; Mann-Whitney). Post-treatment Gal-3 levels were 11.3 ± 3.7 (HELP; range 4.5-16.3) and 11.3 ± 3.8 (DSA; range 7.5-20.7) ng/mL. CONCLUSIONS: Circulating Gal-3 levels showed a statistically significant decrease in humans undergoing therapeutic LA. Although absolute Gal-3 reduction was ≈19-23%, this effect, combined with reducing atherogenic LDL and other inflammation mediators (e.g., CRP, fibrinogen, Lp-PLA2 ), may enhance apheresis clinical benefits. Applying new Gal-3-specific extraction technologies to apheresis may be advantageous in treating diverse pathologies that are promoted by elevated plasma Gal-3. J. Clin. Apheresis 31:388-392, 2016. © 2015 Wiley Periodicals, Inc.


Assuntos
Remoção de Componentes Sanguíneos/métodos , Galectina 3/sangue , Lipoproteína(a)/isolamento & purificação , Remoção de Componentes Sanguíneos/instrumentação , Remoção de Componentes Sanguíneos/normas , Sulfato de Dextrana/uso terapêutico , Heparina/uso terapêutico , Humanos , Hipercolesterolemia/terapia , Mediadores da Inflamação/sangue , Lipoproteínas LDL/sangue , Pessoa de Meia-Idade
8.
PLoS One ; 8(10): e76407, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24098493

RESUMO

While there are a number of licensed veterinary DNA vaccines, to date, none have been licensed for use in humans. Here, we demonstrate that a novel technology designed to enhance the immunogenicity of DNA vaccines protects against lethal herpes simplex virus 2 (HSV-2) challenge in a murine model. Polynucleotides were modified by use of a codon optimization algorithm designed to enhance immune responses, and the addition of an ubiquitin-encoding sequence to target the antigen to the proteasome for processing and to enhance cytotoxic T cell responses. We show that a mixture of these codon-optimized ubiquitinated and non-ubiquitinated constructs encoding the same viral envelope protein, glycoprotein D, induced both B and T cell responses, and could protect against lethal viral challenge and reduce ganglionic latency. The optimized vaccines, subcloned into a vector suitable for use in humans, also provided a high level of protection against the establishment of ganglionic latency, an important correlate of HSV reactivation and candidate endpoint for vaccines to proceed to clinical trials.


Assuntos
Herpes Simples/imunologia , Herpes Simples/prevenção & controle , Herpesvirus Humano 2/imunologia , Vacinas de DNA/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Códon , Feminino , Herpes Simples/mortalidade , Herpesvirus Humano 2/genética , Camundongos , Subpopulações de Linfócitos T/imunologia , Ubiquitinação , Vacinas de DNA/administração & dosagem , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
9.
J Clin Lipidol ; 7(2): 140-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23415433

RESUMO

BACKGROUND: Niacin, or vitamin B3, when used in high doses can significantly improve the levels of all major lipoproteins. Despite these benefits, the use of niacin is greatly limited secondary to benign yet bothersome cutaneous flushing primarily involving the face and upper extremities. Pretreatment with aspirin or other prostaglandin inhibitors has demonstrated significant reductions in niacin-induced flushing (NIF), but other treatment options are needed. Clinical and anecdotal evidence suggests the ingestion of pectin-containing fruits (eg, apple) mitigates NIF; however, clinical trials evaluating this are nonexistent. OBJECTIVE: That pretreatment with encapsulated apple pectin would limit the incidence, severity, time of initiation, and duration of NIF. METHODS: We enrolled 100 niacin-naïve subjects (n = 25 per group) and preteated them in a double-blind manner with apple pectin, apple pectin + aspirin, aspirin, or placebo, followed by a one-time 1000 mg dose of niacin extended-release (niacin ER). Subjects then assessed major flushing parameters hourly for the next 6 hours with a validated visual analog scale. RESULTS: Apple pectin and aspirin each significantly lowered the duration of NIF and produced nonsignificant but positive improvements in all other major flushing parameters compared with placebo. CONCLUSION: Apple pectin may potentially be an alternative to aspirin for the prevention of NIF. Larger trials are needed to further evaluate the benefit of pectin on NIF.


Assuntos
Rubor/dietoterapia , Hipolipemiantes/efeitos adversos , Malus/metabolismo , Niacina/efeitos adversos , Pectinas/uso terapêutico , Adolescente , Adulto , Idoso , Anti-Inflamatórios não Esteroides/uso terapêutico , Aspirina/uso terapêutico , Método Duplo-Cego , Feminino , Rubor/induzido quimicamente , Rubor/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Efeito Placebo , Adulto Jovem
10.
J Clin Invest ; 122(2): 558-68, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22214850

RESUMO

Hypercholesterolemia is a major risk factor for atherosclerosis. It also is associated with platelet hyperactivity, which increases morbidity and mortality from cardiovascular disease. However, the mechanisms by which hypercholesterolemia produces a procoagulant state remain undefined. Atherosclerosis is associated with accumulation of oxidized lipoproteins within atherosclerotic lesions. Small quantities of oxidized lipoproteins are also present in the circulation of patients with coronary artery disease. We therefore hypothesized that hypercholesterolemia leads to elevated levels of oxidized LDL (oxLDL) in plasma and that this induces expression of the procoagulant protein tissue factor (TF) in monocytes. In support of this hypothesis, we report here that oxLDL induced TF expression in human monocytic cells and monocytes. In addition, patients with familial hypercholesterolemia had elevated levels of plasma microparticle (MP) TF activity. Furthermore, a high-fat diet induced a time-dependent increase in plasma MP TF activity and activation of coagulation in both LDL receptor-deficient mice and African green monkeys. Genetic deficiency of TF in bone marrow cells reduced coagulation in hypercholesterolemic mice, consistent with a major role for monocyte-derived TF in the activation of coagulation. Similarly, a deficiency of either TLR4 or TLR6 reduced levels of MP TF activity. Simvastatin treatment of hypercholesterolemic mice and monkeys reduced oxLDL, monocyte TF expression, MP TF activity, activation of coagulation, and inflammation, without affecting total cholesterol levels. Our results suggest that the prothrombotic state associated with hypercholesterolemia is caused by oxLDL-mediated induction of TF expression in monocytes via engagement of a TLR4/TLR6 complex.


Assuntos
Anticolesterolemiantes/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Hipercolesterolemia/sangue , Monócitos/metabolismo , Sinvastatina/farmacologia , Tromboplastina/metabolismo , Animais , Coagulação Sanguínea/fisiologia , Células Cultivadas , Chlorocebus aethiops , Humanos , Lipoproteínas LDL/metabolismo , Masculino , Camundongos , Receptores de LDL/genética , Receptores de LDL/metabolismo , Trombose , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Receptor 6 Toll-Like/genética , Receptor 6 Toll-Like/metabolismo
11.
Biopolymers ; 94(3): 307-13, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20013812

RESUMO

alpha-Conotoxins are multiple disulfide bond containing peptides that are isolated from venomous marine cone snails. They display remarkable selectivity for different subtypes of nicotinic acetylcholine receptors (nAChRs). While alpha-conotoxins display poor resistance to in vivo degradation by proteases, which limits their use as drug leads, N-to-C cyclization via an oligopeptide spacer unit has been previously shown to improve stability. However, the effect of N-to-C cyclization on the formation of the disulfide bond framework is not fully understood. Four N-to-C cyclic analogs of alpha-conotoxin ImI; cImI-A, cImI-betaA, cImI-AG, and cImI-AGG were synthesized to evaluate the effect of oligopeptide spacer length on disulfide bond selectivity and stability to proteolysis. Different ratios of disulfide bond isomers were obtained for each analog using a nonselective random disulfide bond forming strategy, which was dependent on the length of the spacer. To identify each isomer obtained using the random strategy, and to gain access to disulfide bond isomers otherwise unattainable using the random strategy, both the native (globular) and ribbon isomers were synthesized in good yield and purity using a selective orthogonal cysteine protecting group strategy. As such, a random oxidation strategy showed a clear preference for the ribbon isomer in cImI-A. The cyclic globular isomers showed a high resistance to enzymatic degradation compared to the ribbon isomers, with the cImI-A and cImI-AG globular isomers demonstrating the highest stability. These results suggest that cyclization can improve the biochemical stability of conotoxins with potential applications in the development of drugs.


Assuntos
Conotoxinas/química , Dissulfetos/química , Peptídeos/química , Sequência de Aminoácidos , Animais , Conotoxinas/genética , Isomerismo , Dados de Sequência Molecular , Peptídeos/síntese química , Peptídeos/genética , Conformação Proteica
12.
J Biol Chem ; 279(45): 46858-67, 2004 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-15328347

RESUMO

The cyclotides are the largest family of naturally occurring circular proteins. The mechanism by which the termini of these gene-encoded proteins are linked seamlessly with a peptide bond to form a circular backbone is unknown. Here we report cyclotide-encoding cDNA sequences from the plant Viola odorata and compare them with those from an evolutionarily distinct species, Oldenlandia affinis. Individual members of this multigene family encode one to three mature cyclotide domains. These domains are preceded by N-terminal repeat regions (NTRs) that are conserved within a plant species but not between species. We have structurally characterized peptides corresponding to these NTRs and show that, despite them having no sequence homology, they form a structurally conserved alpha-helical motif. This structural conservation suggests a vital role for the NTR in the in vivo folding, processing, or detoxification of cyclotide domains from the precursor protein.


Assuntos
DNA Complementar/química , Genes de Plantas , Sequência de Aminoácidos , Animais , Asteraceae , Sequência Conservada , Cristalografia por Raios X , Ciclotídeos/química , DNA Complementar/metabolismo , Evolução Molecular , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Família Multigênica , Peptídeos/química , Conformação Proteica , Dobramento de Proteína , Estrutura Terciária de Proteína , Prótons , RNA/química , Homologia de Sequência de Aminoácidos , Viola
13.
J Med Chem ; 46(7): 1266-72, 2003 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-12646037

RESUMO

The alpha-conotoxin MII is a two disulfide bridge containing, 16 amino acid long peptide toxin isolated from the marine snail Conus magus. This toxin has been found to be a highly selective and potent inhibitor of neuronal nicotinic acetylcholine receptors (nAChRs) of the subtype alpha3beta2. To improve the bioavailability of this peptide, two lipidic analogues of MII have been synthesized, the first by coupling 2-amino-d,l-dodecanoic acid (Laa) to the N terminus (LaaMII) and the second by replacing Asn5 in the MII sequence with this lipoamino acid (5LaaMII). Both lipidic linear peptides were then oxidized under standard conditions. (1)H NMR shift analysis of these peptides and comparison with the native MII peptide showed that the tertiary structure of the N-conjugated analogue, LaaMII, was consistent with that of the native conotoxin, whereas the 5LaaMII analogue formed the correct disulfide bridges but failed to adopt the native helical tertiary structure. The N terminus conjugate was also found to inhibit nAChRs of the subtype alpha3beta2 with equal potency to the parent peptide, whereas the 5LaaMII analogue showed no inhibitory activity. The active LaaMII analogue was found to exhibit significantly improved permeability across Caco-2 cell monolayers compared to the native MII, and both peptides showed negligible toxicity.


Assuntos
Conotoxinas/síntese química , Ácidos Láuricos/química , Antagonistas Nicotínicos/síntese química , Peptídeos Cíclicos/síntese química , Sequência de Aminoácidos , Animais , Células CACO-2 , Conotoxinas/química , Conotoxinas/farmacocinética , Conotoxinas/toxicidade , Gânglios Parassimpáticos/citologia , Hemólise , Humanos , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Masculino , Dados de Sequência Molecular , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Antagonistas Nicotínicos/química , Antagonistas Nicotínicos/farmacocinética , Antagonistas Nicotínicos/toxicidade , Técnicas de Patch-Clamp , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacocinética , Peptídeos Cíclicos/toxicidade , Permeabilidade , Estrutura Terciária de Proteína , Ratos , Ratos Sprague-Dawley , Receptores Nicotínicos/efeitos dos fármacos , Receptores Nicotínicos/fisiologia , Solubilidade , Relação Estrutura-Atividade
14.
J Biol Chem ; 277(50): 48849-57, 2002 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-12376538

RESUMO

alpha-Conotoxin AuIB and a disulfide bond variant of AuIB have been synthesized to determine the role of disulfide bond connectivity on structure and activity. Both of these peptides contain the 15 amino acid sequence GCCSYPPCFATNPDC, with the globular (native) isomer having the disulfide connectivity Cys(2-8 and 3-15) and the ribbon isomer having the disulfide connectivity Cys(2-15 and 3-8). The solution structures of the peptides were determined by NMR spectroscopy, and their ability to block the nicotinic acetylcholine receptors on dissociated neurons of the rat parasympathetic ganglia was examined. The ribbon disulfide isomer, although having a less well defined structure, is surprisingly found to have approximately 10 times greater potency than the native peptide. To our knowledge this is the first demonstration of a non-native disulfide bond isomer of a conotoxin exhibiting greater biological activity than the native isomer.


Assuntos
Conotoxinas/química , Conotoxinas/farmacologia , Dissulfetos/química , Sequência de Aminoácidos , Animais , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Secundária de Proteína , Ratos , Relação Estrutura-Atividade
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