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1.
PLoS One ; 19(3): e0300684, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38512858

RESUMO

Brazilian coastal archaeology is renowned for its numerous and large shellmounds (sambaquis), which had been continuously occupied from at least 8000 to 1000 years cal BP. However, changes in their structure and material culture in the late Holocene have led to different hypotheses concerning their ecological and cultural changes. The archaeological site Galheta IV (ca. 1300 to 500 years cal BP) offers new insights into the complexity of the late coastal occupation in southern Brazil. Our attempt was to determine whether Galheta IV can be classified as a sambaqui site, or if it belongs to a Southern proto-Jê settlement. Here, we reassessed Galheta's collections and applied a multi-proxy approach using: new 14C dates, zooarchaeology, δ13C and δ15N isotopes in bulk collagen and 87Sr/86Srenamel isotopic ratios from eight human individuals, ceramics analysis, and FTIR. The results indicate an intense exploitation of marine resources, with an area designated for processing animals located at the opposite side of the funerary areas. Bone tools and specific species of animals were found as burial accompaniments. No evidence of human cremations was detected. 87Sr/86Sr results indicate that the eight human individuals always lived on the coast, and did not come from the inland. The pottery analysis confirms the association with Itararé-Taquara, but contrary to what was assumed by previous studies, the pottery seems related to other coastal sites, and not to the highlands. In light of these findings, we propose that Galheta IV can be considered a funerary mound resulting from long and continuous interactions between shellmound and Southern proto-Jê populations. This study not only enhances our understanding of the late coastal occupation dynamics in southern Brazil but also underscores its importance in reshaping current interpretations of shellmound cultural changes over time.


Assuntos
Arqueologia , Isótopos de Estrôncio , Humanos , Animais , Brasil , Arqueologia/métodos
2.
PLoS One ; 16(3): e0247965, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33690652

RESUMO

Current archaeological paradigm proposes that the first peopling of the Americas does not exceed the Last Glacial Maximum period. In this context, the acceptance of the anthropogenic character of the earliest stone artefacts generally rests on the presence of projectile points considered no more as typocentric but as typognomonic, since it allows, by itself, to certify the human character of the other associated artefacts. In other words, without this presence, nothing is certain. Archaeological research at Piauí (Brazil) attests to a Pleistocene human presence between 41 and 14 cal kyr BP, without any record of lithic projectile points. Here, we report the discovery and interpretation of an unusual stone artefact in the Vale da Pedra Furada site, in a context dating back to 24 cal kyr BP. The knapping stigmata and macroscopic use-wear traces reveal a conception centred on the configuration of double bevels and the production in the same specimen of at least two successive artefacts with probably different functions. This piece unambiguously presents an anthropic character and reveals a technical novelty during the Pleistocene occupation of South America.


Assuntos
Arqueologia/métodos , Fósseis/diagnóstico por imagem , Brasil , História Antiga , Humanos , Invenções/história , Datação Radiométrica/métodos , Solo/química
3.
PLoS One ; 15(5): e0232379, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407324

RESUMO

Zinc (Zn) isotope ratios of dental enamel are a promising tracer for dietary reconstruction in archeology, but its use is still in its infancy. A recent study demonstrated a high risk of Zn contamination from nitrile, and latex gloves used during chemical sample preparation. Here we assess the potential impact of the use of such gloves during enamel sampling on the Zn isotope composition of teeth from a population of early Holocene hunter gatherers from Lapa do Santo, Lagoa Santa, Minas Gerais, Brazil. We first examined the amount of Zn and its isotopic composition released from the gloves used in this study by soaking them in weak nitric acid and water. We compared Zn isotope ratios obtained from teeth that were sampled wearing nitrile, latex or no gloves. Finally, we performed a linear mixed model (LMM) to investigate post hoc the relationship between the gloves used for sampling and the Zn isotope variability in dental enamel. We found that the gloves used in this study released a similar amount of Zn compared to previous work, but only in acidic solution. Zn isotope ratios of teeth and the LMM identified no sign of significant Zn coming from the gloves when teeth were handled for enamel sampling. We hypothesize that Zn in gloves is mostly released by contact with acids. We found that the main source of Zn isotope variability in the Lapa do Santo population was related to the developmental stage of the tooth tissues sampled. We report identical results for two individuals coming from a different archeological context. Tooth enamel formed in utero and/or during the two first years of life showed higher Zn isotope ratios than enamel formed after weaning. More work is required to systematically investigate if Zn isotopes can be used as a breastfeeding tracer.


Assuntos
Arqueologia , Dieta , Dente/química , Isótopos de Zinco/análise , Artefatos , Brasil , Criança , Humanos , Lactente , Desmame
4.
PLoS One ; 14(12): e0225927, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31821345

RESUMO

Complete plant inventories of large areas of forests in the moderate and boreal zone have thus far been infeasible and have also not been published. The use of orienteering maps (O-maps) for sampling for inventories was tested. In the sampling method presented herein, the "O-map/way method", O-maps were used for controlled and systematic inspection and sampling, making it possible to carry out successfully complete plant taxon and site inventories of large forest areas (1 to 100 ha). O-maps are much more suitable than the best national or similar topographic maps (NT-maps) for plant inventories in forests; O-maps have many advantages (smaller scale/better resolution, better legibility, internationally standardization, information on vegetation and accessibility), and they contain more small objects, ways (= tracks of any size; roads), and lines and thus have much smaller subareas that allow good orientation and systematic screening for plants. For the example of plant taxon inventories in 6 target areas of 25-85 ha of Swiss midland forests in the moderate/colline zone, the O-map/way method (all accessible areas are screened) was shown to be clearly superior to alternative sampling methods (partial areas screened), such as the NT-map/way method or a plot method, in which only 79.6±6.7% or 34.5±6.6%, respectively, of the taxa found by the O-map/way method were recorded. Taxa detected only by the O-map/way method were shown to be relatively rare at a local as well as at a national scale. The O-map/way method could also be successfully applied to the inventory of plant sites in large forest areas: As shown by the distribution of the sites of five plant species in a target area of 30.1 ha, the great majority of plant sites were detected only by the O-map/way method; but only a few sites were detected by the alternative methods. As O-maps for forests are widely available in many countries, the O-map/way method might allow for complete inventories and other studies in large forest areas.


Assuntos
Monitoramento Ambiental , Florestas , Plantas/classificação , Modelos Teóricos , Suíça
5.
Am J Phys Anthropol ; 169(2): 322-331, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30972753

RESUMO

OBJECTIVES: Platyrrhines constitute a diverse clade, with the modern Atelidae exhibiting the most variation in cranial and endocast morphology. The processes responsible for this diversification are not well understood. Here, we present a geometric morphometric study describing variation in cranial and endocranial shape of 14 species of Alouatta, Ateles, Brachyteles, and Lagothrix and two extinct taxa, Cartelles and Caipora. METHODS: We examined cranial and endocranial shape variation among species using images reconstructed from CT scans and geometric morphometric techniques based on three-dimensional landmarks and semilandmarks. Principal components analyses were used to explore variation, including the Procrustes shape coordinates, summing the logarithm of the Centroid Size, the common allometric component, and residual shape components. RESULTS: Differences in endocranial shape are related to a relative increase or decrease in the volume of the neocortex region with respect to brainstem and cerebellum regions. The relative position of the brainstem varies from a posterior position in Alouatta to a more ventral position in Ateles. The shape of both the cranium and endocast of Caipora is within the observed variation of Brachyteles. Cartelles occupies the most differentiated position relative to the extant taxa, especially in regards to its endocranial shape. CONCLUSIONS: The pattern of variation in the extant species in endocranial shape is similar to the variation observed in previous cranial studies, with Alouatta as an outlier. The similarities between Caipora and Brachyteles were unexpected and intriguing given the frugivorous adaptations inferred from the fossil's dentition. Our study shows the importance of considering both extant and fossil species when studying diversification of complex traits.


Assuntos
Atelidae/anatomia & histologia , Evolução Biológica , Encéfalo/anatomia & histologia , Crânio/anatomia & histologia , Animais , Antropologia Física , Atelidae/fisiologia , Encéfalo/fisiologia , Feminino , Fósseis , Masculino , Crânio/diagnóstico por imagem , Crânio/fisiologia , Tomografia Computadorizada por Raios X
6.
PLoS One ; 13(12): e0208999, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30566462

RESUMO

That great ape endocranial shape development persists into adolescence indicates that the splanchnocranium succeeds brain growth in driving endocranial development. However, the extent of this splanchnocranial influence is unknown. We applied two-block partial least squares analyses of Procrustes shape variables on an ontogenetic series of great ape crania to explore the covariation of the endocranium (the internal braincase) and splanchnocranium (face, or viscerocranium). We hypothesized that a transition between brain growth and splanchnocranial development in the establishment of final endocranial form would be manifest as a change in the pattern of shape covariation between early and adolescent ontogeny. Our results revealed a strong pattern of covariation between endocranium and splanchnocranium, indicating that chimpanzees, gorillas, and orangutans share a common tempo and mode of morphological integration from the eruption of the deciduous dentition onwards to adulthood: a reflection of elongating endocranial shape and continuing splanchnocranial prognathism. Within this overarching pattern, we noted that species variation exists in magnitude and direction, and that the covariation between the splanchnocranium and endocranium is somewhat weaker in early infancy compared to successive age groups. When correcting our covariation analyses for allometry, we found that an ontogenetic signal remains, signifying that allometric variation alone is insufficient to account for all endocranial-splanchnocranial developmental integration. Finally, we assessed the influence of the cranial base, which acts as the interface between the face and endocranium, on the shape of the vault using thin-plate spline warping. We found that not all splanchnocranial shape changes during development are tightly integrated with endocranial shape. This suggests that while the developmental expansion of the brain is the main driver of endocranial shape during early ontogeny, endocranial development from infancy onwards is moulded by the splanchnocranium in conjunction with the neurocranium.


Assuntos
Hominidae/anatomia & histologia , Base do Crânio/anatomia & histologia , Crânio/anatomia & histologia , Crânio/crescimento & desenvolvimento , Animais , Evolução Biológica , Encéfalo/anatomia & histologia , Encéfalo/crescimento & desenvolvimento , Feminino , Análise dos Mínimos Quadrados , Masculino , Modelos Biológicos , Crânio/diagnóstico por imagem , Base do Crânio/diagnóstico por imagem , Base do Crânio/crescimento & desenvolvimento , Especificidade da Espécie , Tomografia Computadorizada por Raios X
7.
Science ; 362(6419)2018 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-30409807

RESUMO

Studies of the peopling of the Americas have focused on the timing and number of initial migrations. Less attention has been paid to the subsequent spread of people within the Americas. We sequenced 15 ancient human genomes spanning from Alaska to Patagonia; six are ≥10,000 years old (up to ~18× coverage). All are most closely related to Native Americans, including those from an Ancient Beringian individual and two morphologically distinct "Paleoamericans." We found evidence of rapid dispersal and early diversification that included previously unknown groups as people moved south. This resulted in multiple independent, geographically uneven migrations, including one that provides clues of a Late Pleistocene Australasian genetic signal, as well as a later Mesoamerican-related expansion. These led to complex and dynamic population histories from North to South America.


Assuntos
Genoma Humano , Migração Humana , Índios Norte-Americanos/genética , Conjuntos de Dados como Assunto , Ásia Oriental/etnologia , Genômica , Humanos , América do Norte , Polimorfismo de Nucleotídeo Único , Dinâmica Populacional , Sibéria/etnologia , América do Sul
8.
Stem Cell Res ; 26: 47-54, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29227832

RESUMO

The different facets of macrophages allow them to play distinct roles in tissue homeostasis, tissue repair and in response to infections. Individuals displaying dysregulated macrophage functions are proposed to be prone to inflammatory disorders or infections. However, this being a cause or a consequence of the pathology remains often unclear. In this context, we isolated and expanded CD34+ HSCs from healthy blood donors and derived them into CD14+ myeloid progenitors which were further enriched and differentiated into macrophages. Aiming for a comprehensive phenotypic profiling, we generated whole-cell mass spectrometry (WCMS) fingerprints of cell samples collected along the different stages of the differentiation process to build a predictive model using a linear discriminant analysis based on principal components. Through the capacity of the model to accurately predict sample's identity of a validation set, we demonstrate that WCMS profiles obtained from bona fide blood monocytes and respectively derived macrophages mirror profiles obtained from equivalent HSC derivatives. Finally, HSC-derived macrophage functionalities were assessed by quantifying cytokine and chemokine responses to a TLR agonist in a 34-plex luminex assay and by measuring their capacity to phagocytise mycobacteria. These functional read-outs could not discriminate blood monocytes-derived from HSC-derived macrophages. To conclude, we propose that this method opens new avenues to distinguish the impact of human genetics on the dysregulated biological properties of macrophages in pathological conditions.


Assuntos
Diferenciação Celular , Quimiocinas/metabolismo , Citocinas/metabolismo , Células-Tronco Hematopoéticas/citologia , Macrófagos/citologia , Monócitos/citologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Macrófagos/metabolismo , Espectrometria de Massas , Monócitos/metabolismo , Fenótipo
9.
Sci Adv ; 3(2): e1602289, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28261661

RESUMO

The nature and timing of the peopling of the Americas is a subject of intense debate. In particular, it is unclear whether high levels of between-group craniometric diversity in South America result from multiple migrations or from local diversification processes. Previous attempts to explain this diversity have largely focused on testing alternative dispersal or gene flow models, reaching conflicting or inconclusive results. Here, a novel analytical framework is applied to three-dimensional geometric morphometric data to partition the effects of population divergence from geographically mediated gene flow to understand the ancestry of the early South Americans in the context of global human history. The results show that Paleoamericans share a last common ancestor with contemporary Native American groups outside, rather than inside, the Americas. Therefore, and in accordance with some recent genomic studies, craniometric data suggest that the New World was populated by multiple waves of dispersion from northeast Asia throughout the late Pleistocene and early Holocene.


Assuntos
Cefalometria , Índios Sul-Americanos , Crânio/anatomia & histologia , Feminino , História Antiga , Humanos , Masculino , América do Sul
10.
BMC Microbiol ; 16(1): 289, 2016 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-27938342

RESUMO

BACKGROUND: Numerous pathogens and opportunistic pathogens have been detected in harvested rainwater. Developing countries, in particular, require time- and cost-effective treatment strategies to improve the quality of this water source. The primary aim of the current study was thus to compare solar pasteurization (SOPAS; 70 to 79 °C; 80 to 89 °C; and ≥90 °C) to solar disinfection (SODIS; 6 and 8 hrs) for their efficiency in reducing the level of microbial contamination in harvested rainwater. The chemical quality (anions and cations) of the SOPAS and SODIS treated and untreated rainwater samples were also monitored. RESULTS: While the anion concentrations in all the samples were within drinking water guidelines, the concentrations of lead (Pb) and nickel (Ni) exceeded the guidelines in all the SOPAS samples. Additionally, the iron (Fe) concentrations in both the SODIS 6 and 8 hr samples were above the drinking water guidelines. A >99% reduction in Escherichia coli and heterotrophic bacteria counts was then obtained in the SOPAS and SODIS samples. Ethidium monoazide bromide quantitative polymerase chain reaction (EMA-qPCR) analysis revealed a 94.70% reduction in viable Legionella copy numbers in the SOPAS samples, while SODIS after 6 and 8 hrs yielded a 50.60% and 75.22% decrease, respectively. Similarly, a 99.61% reduction in viable Pseudomonas copy numbers was observed after SOPAS treatment, while SODIS after 6 and 8 hrs yielded a 47.27% and 58.31% decrease, respectively. CONCLUSION: While both the SOPAS and SODIS systems reduced the indicator counts to below the detection limit, EMA-qPCR analysis indicated that SOPAS treatment yielded a 2- and 3-log reduction in viable Legionella and Pseudomonas copy numbers, respectively. Additionally, SODIS after 8 hrs yielded a 2-log and 1-log reduction in Legionella and Pseudomonas copy numbers, respectively and could be considered as an alternative, cost-effective treatment method for harvested rainwater.


Assuntos
Desinfecção/métodos , Pasteurização/métodos , Chuva , Purificação da Água/métodos , Carga Bacteriana , Países em Desenvolvimento , Desinfecção/economia , Desinfecção/instrumentação , Água Potável/análise , Água Potável/microbiologia , Água Potável/normas , Monitoramento Ambiental , Escherichia coli/crescimento & desenvolvimento , Pasteurização/economia , Pasteurização/instrumentação , Luz Solar , Microbiologia da Água , Purificação da Água/economia , Purificação da Água/instrumentação
11.
PLoS One ; 10(10): e0138090, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26465141

RESUMO

Recent South Americans have been described as presenting high regional cranial morphological diversity when compared to other regions of the world. This high diversity is in accordance with linguistic and some of the molecular data currently available for the continent, but the origin of this diversity has not been satisfactorily explained yet. Here we explore if this high morphological variation was already present among early groups in South America, in order to refine our knowledge about the timing and origins of the modern morphological diversity. Between-group (Fst estimates) and within-group variances (trace of within-group covariance matrix) of the only two early American population samples available to date (Lagoa Santa and Sabana de Bogotá) were estimated based on linear craniometric measurements and compared to modern human cranial series representing six regions of the world, including the Americas. The results show that early Americans present moderate within-group diversity, falling well within the range of modern human groups, despite representing almost three thousand years of human occupation. The between-group variance apportionment is very low between early Americans, but is high among recent South American groups, who show values similar to the ones observed on a global scale. Although limited to only two early South American series, these results suggest that the high morphological diversity of native South Americans was not present among the first human groups arriving in the continent and must have originated during the Middle Holocene, possibly due to the arrival of new morphological diversity coming from Asia during the Holocene.


Assuntos
Evolução Biológica , Crânio/anatomia & histologia , Biodiversidade , Cefalometria , Coleta de Dados , Emigração e Imigração , Etnicidade , Fósseis , Geografia , Humanos , Índios Norte-Americanos , Índios Sul-Americanos , Valores de Referência , América do Sul
12.
PLoS One ; 10(9): e0137456, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26397983

RESUMO

We present here evidence for an early Holocene case of decapitation in the New World (Burial 26), found in the rock shelter of Lapa do Santo in 2007. Lapa do Santo is an archaeological site located in the Lagoa Santa karst in east-central Brazil with evidence of human occupation dating as far back as 11.7-12.7 cal kyBP (95.4% interval). An ultra-filtered AMS age determination on a fragment of the sphenoid provided an age range of 9.1-9.4 cal kyBP (95.4% interval) for Burial 26. The interment was composed of an articulated cranium, mandible and first six cervical vertebrae. Cut marks with a v-shaped profile were observed in the mandible and sixth cervical vertebra. The right hand was amputated and laid over the left side of the face with distal phalanges pointing to the chin and the left hand was amputated and laid over the right side of the face with distal phalanges pointing to the forehead. Strontium analysis comparing Burial 26's isotopic signature to other specimens from Lapa do Santo suggests this was a local member of the group. Therefore, we suggest a ritualized decapitation instead of trophy-taking, testifying for the sophistication of mortuary rituals among hunter-gatherers in the Americas during the early Archaic period. In the apparent absence of wealth goods or elaborated architecture, Lapa do Santo's inhabitants seemed to use the human body to express their cosmological principles regarding death.


Assuntos
Arqueologia , Decapitação/história , Osso e Ossos/anatomia & histologia , Brasil , Sepultamento , Geografia , História Antiga , Humanos , Datação Radiométrica , Isótopos de Estrôncio
13.
J Biol Chem ; 290(24): 15210-8, 2015 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-25918157

RESUMO

Macrophages are important cellular effectors in innate immune responses and play a major role in autoimmune diseases such as rheumatoid arthritis. Cancer Osaka thyroid (COT) kinase, also known as mitogen-activated protein kinase kinase kinase 8 (MAP3K8) and tumor progression locus 2 (Tpl-2), is a serine-threonine (ST) kinase and is a key regulator in the production of pro-inflammatory cytokines in macrophages. Due to its pivotal role in immune biology, COT kinase has been identified as an attractive target for pharmaceutical research that is directed at the discovery of orally available, selective, and potent inhibitors for the treatment of autoimmune disorders and cancer. The production of monomeric, recombinant COT kinase has proven to be very difficult, and issues with solubility and stability of the enzyme have hampered the discovery and optimization of potent and selective inhibitors. We developed a protocol for the production of recombinant human COT kinase that yields pure and highly active enzyme in sufficient yields for biochemical and structural studies. The quality of the enzyme allowed us to establish a robust in vitro phosphorylation assay for the efficient biochemical characterization of COT kinase inhibitors and to determine the x-ray co-crystal structures of the COT kinase domain in complex with two ATP-binding site inhibitors. The structures presented in this study reveal two distinct ligand binding modes and a unique kinase domain architecture that has not been observed previously. The structurally versatile active site significantly impacts the design of potent, low molecular weight COT kinase inhibitors.


Assuntos
MAP Quinase Quinase Quinases/química , Dobramento de Proteína , Proteínas Proto-Oncogênicas/química , Cristalografia por Raios X , Humanos , Modelos Moleculares , Conformação Proteica , Proteínas Recombinantes/química
14.
Am J Phys Anthropol ; 157(2): 202-16, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25663638

RESUMO

The Botocudo Indians were hunter-gatherer groups that occupied the East-Central regions of Brazil decimated during the colonial period in the country. During the 19th century, craniometric studies suggested that the Botocudo resembled more the Paleoamerican population of Lagoa Santa than typical Native Americans groups. These results suggest that the Botocudo Indians might represent a population that retained the biological characteristics of early groups of the continent, remaining largely isolated from groups that gave origin to the modern Native South American variation. Moreover, recently, some of the Botocudo remains have been shown to have mitochondrial and autosomal DNA lineages currently found in Polynesian populations. Here, we explore the morphological affinities of Botocudo skulls within a worldwide context. Distinct multivariate analyses based on 32 craniometric variables show that 1) the two individuals with Polynesian DNA sequences have morphological characteristics that fall within the Polynesian and Botocudo variation, making their assignation as Native American specimens problematic, and 2) there are high morphological affinities between Botocudo, Early Americans, and the Polynesian series of Easter Island, which support the early observations that the Botocudo can be seen as retaining the Paleoamerican morphology, particularly when the neurocranium is considered. Although these results do not elucidate the origin of the Polynesian DNA lineages among the Botocudo, they support the hypothesis that the Botocudo represent a case of late survival of ancient Paleoamerican populations, retaining the morphological characteristics of ancestral Late Pleistocene populations from Asia.


Assuntos
Cefalometria , Índios Sul-Americanos/estatística & dados numéricos , Crânio/anatomia & histologia , Antropologia Física , Brasil , Feminino , Migração Humana , Humanos , Índios Sul-Americanos/genética , Masculino , Havaiano Nativo ou Outro Ilhéu do Pacífico , Polinésia
15.
Bioorg Med Chem Lett ; 21(24): 7367-72, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22078216

RESUMO

The present study describes a novel series of ATP-competitive PKC inhibitors based on the 2,6-naphthyridine template. Example compounds potently inhibit the novel Protein Kinase C (PKC) isotypes δ, ε, η, θ (in particular PKCε/η, and display a 10-100-fold selectivity over the classical PKC isotypes. The prototype compound 11 was found to inhibit PKCθ-dependent pathways in vitro and in vivo. In vitro, a-CD3/a-CD28-induced lymphocyte proliferation could be effectively blocked in 10% rat whole blood. In mice, 11 dose-dependently inhibited Staphylococcus aureus enterotoxin B-triggered IL-2 serum levels after oral dosing.


Assuntos
Naftiridinas/química , Proteína Quinase C/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Administração Oral , Animais , Sítios de Ligação , Simulação por Computador , Cristalografia por Raios X , Enterotoxinas/toxicidade , Interleucina-2/sangue , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Camundongos , Naftiridinas/síntese química , Naftiridinas/farmacocinética , Proteína Quinase C/metabolismo , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacocinética , Estrutura Terciária de Proteína , Ratos , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
16.
J Biomol NMR ; 51(4): 449-56, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21964698

RESUMO

An easy to use and robust approach for amino acid type selective isotope labeling in insect cells is presented. It relies on inexpensive commercial media and can be implemented in laboratories without sophisticated infrastructure. In contrast to previous protocols, where either high protein amounts or high incorporation ratios were obtained, here we achieve both at the same time. By supplementing media with a well considered amount of yeast extract, similar protein amounts as with full media are obtained, without compromising on isotope incorporation. In single and dual amino acid labeling experiments incorporation ratios are consistently ≥90% for all amino acids tested. This enables NMR studies of eukaryotic proteins and their interactions even for proteins with low expression levels. We show applications with human kinases, where protein-ligand interactions are characterized by 2D [(15)N, (1)H]- and [(13)C, (1)H]-HSQC spectra.


Assuntos
Marcação por Isótopo/métodos , Proteínas Proto-Oncogênicas c-akt/análise , Proteínas Proto-Oncogênicas c-akt/química , Aminoácidos/análise , Aminoácidos/química , Aminoácidos/metabolismo , Animais , Baculoviridae/química , Células Cultivadas , Humanos , Insetos , Ressonância Magnética Nuclear Biomolecular/métodos
18.
Nat Chem Biol ; 6(9): 660-6, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20711197

RESUMO

Bisphosphonates are potent inhibitors of farnesyl pyrophosphate synthase (FPPS) and are highly efficacious in the treatment of bone diseases such as osteoporosis, Paget's disease and tumor-induced osteolysis. In addition, the potential for direct antitumor effects has been postulated on the basis of in vitro and in vivo studies and has recently been demonstrated clinically in early breast cancer patients treated with the potent bisphosphonate zoledronic acid. However, the high affinity of bisphosphonates for bone mineral seems suboptimal for the direct treatment of soft-tissue tumors. Here we report the discovery of the first potent non-bisphosphonate FPPS inhibitors. These new inhibitors bind to a previously unknown allosteric site on FPPS, which was identified by fragment-based approaches using NMR and X-ray crystallography. This allosteric and druggable pocket allows the development of a new generation of FPPS inhibitors that are optimized for direct antitumor effects in soft tissue.


Assuntos
Difosfonatos , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/análise , Inibidores Enzimáticos/farmacologia , Geraniltranstransferase/antagonistas & inibidores , Regulação Alostérica , Sítio Alostérico , Osso e Ossos/química , Osso e Ossos/metabolismo , Cristalografia por Raios X , Difosfonatos/análise , Difosfonatos/química , Difosfonatos/metabolismo , Difosfonatos/farmacologia , Inibidores Enzimáticos/química , Geraniltranstransferase/metabolismo , Humanos , Imidazóis/análise , Imidazóis/química , Imidazóis/farmacologia , Espectroscopia de Ressonância Magnética , Neoplasias de Tecidos Moles/tratamento farmacológico , Ácido Zoledrônico
19.
Hum Biol ; 82(3): 315-30, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20649387

RESUMO

The statement that pairs of individuals from different populations are often more genetically similar than pairs from the same population is a widespread idea inside and outside the scientific community. Witherspoon et al. ["Genetic similarities within and between human populations," Genetics 176:351-359 (2007)] proposed an index called the dissimilarity fraction (omega) to access in a quantitative way the validity of this statement for genetic systems. Witherspoon demonstrated that, as the number of loci increases, omega decreases to a point where, when enough sampling is available, the statement is false. In this study, we applied the dissimilarity fraction to Howells's craniometric database to establish whether or not similar results are obtained for cranial morphological traits. Although in genetic studies thousands of loci are available, Howells's database provides no more than 55 metric traits, making the contribution of each variable important. To cope with this limitation, we developed a routine that takes this effect into consideration when calculating omega. Contrary to what was observed for the genetic data, our results show that cranial morphology asymptotically approaches a mean omega of 0.3 and therefore supports the initial statement--that is, that individuals from the same geographic region do not form clear and discrete clusters--further questioning the idea of the existence of discrete biological clusters in the human species. Finally, by assuming that cranial morphology is under an additive polygenetic model, we can say that the population history signal of human craniometric traits presents the same resolution as a neutral genetic system dependent on no more than 20 loci.


Assuntos
Cefalometria/estatística & dados numéricos , Variação Genética , Genética Populacional/estatística & dados numéricos , África , Ásia , Cefalometria/métodos , Intervalos de Confiança , Bases de Dados Factuais , Europa (Continente) , Feminino , Marcadores Genéticos , Humanos , Masculino , Fenótipo , Polimorfismo de Nucleotídeo Único , Valores de Referência
20.
J Am Chem Soc ; 132(20): 7043-8, 2010 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-20450175

RESUMO

Allosteric inhibitors of Bcr-Abl have emerged as a novel therapeutic option for the treatment of CML. Using fragment-based screening, a search for novel Abl inhibitors that bind to the myristate pocket was carried out. Here we show that not all myristate ligands are functional inhibitors, but that the conformational state of C-terminal helix_I is a structural determinant for functional activity. We present an NMR-based conformational assay to monitor the conformation of this crucial helix_I and show that myristate ligands that bend helix_I are functional antagonists, whereas ligands that bind to the myristate pocket but do not induce this conformational change are kinase agonists. Activation of c-Abl by allosteric agonists has been confirmed in a biochemical assay.


Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-abl/agonistas , Proteínas Proto-Oncogênicas c-abl/antagonistas & inibidores , Regulação Alostérica , Animais , Ativação Enzimática/efeitos dos fármacos , Humanos , Ligantes , Espectroscopia de Ressonância Magnética , Camundongos , Modelos Moleculares , Ácido Mirístico/metabolismo , Ligação Proteica , Inibidores de Proteínas Quinases/química , Estrutura Secundária de Proteína , Proteínas Proto-Oncogênicas c-abl/química , Proteínas Proto-Oncogênicas c-abl/metabolismo
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