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1.
J Colloid Interface Sci ; 607(Pt 2): 1527-1539, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34583049

RESUMO

The traditional heterogeneous photo-Fenton reaction was mainly restricted by the fewer surface-active sites, low Fe3+/Fe2+ transformation and H2O2 activation efficiency of catalyst. This work designed and fabricated the efficient photo-Fenton Schottky catalysts via a facile electrostatic self-assembly of metallic Fe2N nanoparticles scattering on the surface of red g-C3N4 (ultrathin porous oxygen-doped 2D g-C3N4 nanosheets). The porous morphology and exceptional electrical structure of red g-C3N4 endowed more active sites and facilitated the photoexcited charge separation. Benefitting from the Schottky effect and unique dimensional coupling structure, the strong visible light absorption and fast spatial charge transfer were realized in the Schottky junction system. More strikingly, Fe2N as an efficient co-catalyst was in favor of the trap and export of e-, leading to the Fe3+/Fe2+ transformation and H2O2 activation during the photo-Fenton process. Accordingly, the as-prepared catalysts revealed outstanding activity in photo-Fenton like degradation of tetracycline (TC) although under 5 W white LED light irradiation. Furthermore, the reasonable degradation pathway of TC and corresponding toxicity of the intermediates, as well as the photo-Fenton catalytic mechanism were interpreted and discussed in detail. This study would be a great aid in the development of various Schottky catalysts for heterogeneous photo-Fenton-based environmental remediation systems.


Assuntos
Peróxido de Hidrogênio , Tetraciclina , Catálise , Porosidade , Eletricidade Estática
2.
Dalton Trans ; 50(45): 16488-16492, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34734221

RESUMO

This study demonstrates the rational design and construction of a BiOBr/Bi4MoO9 edge-on heterostructure by growing fish scale-like BiOBr nanosheets on the surface of Bi4MoO9. Such structural and compositional merits expedite electron transport and offer a large interfacial contact area and abundant reactive sites. Optimized BiOBr/Bi4MoO9 exhibited outstanding TC degradation activity.

3.
Dalton Trans ; 50(35): 12147-12158, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34519741

RESUMO

Investigations into novel single-phase phosphors with outstanding luminescence properties and excellent thermal stability are urgently needed in the lighting field. In this work, a crystal phase transition and polyhedron transformation strategy via cation substitution has been proposed. Via controlling the Sr/Ba ratio, the structural evolution of the phosphor from a monocelsian phase to a hexacelsian or feldspar phase and the variation of the local environments of Eu2+ sites are correspondingly studied in Ba0.47-xSr0.50+xAl2Si2O8:0.03Eu. Consequently, the optimal Ba0.17Sr0.80Al2Si2O8:0.03Eu sample exhibits a higher intensity, up to 15.2-fold that of Ba0.97Al2Si2O8:0.03Eu. A narrower full-width-at-half-maximum of 73 nm, better color purity of 82.96%, and an internal quantum yield of 82.3% can be realized. With an increase in temperature, the emission intensity losses of samples from x = -10.0-47.0% are no more than 10.0% at 473 K. Moreover, a WLED (CCT = 5210 K; CRI = 90.3) fabricated using Ba0.17Sr0.80Al2Si2O8:0.03Eu displays warmer white light than one fabricated using BaMgAl10O17:Eu under the same assembly and test conditions. Analysis shows that the structural evolution with reduced polyhedral symmetry and the condensed crystal structure with fortified rigidity are responsible for the improvement in properties. This discovery demonstrates that the utilization of a crystal phase transition and symmetrical coordination is an efficient way to develop novel efficient phosphors and other related materials.

5.
Sci China Life Sci ; 64(8): 1236-1280, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33893979

RESUMO

Evolutionary developmental biology, or Evo-Devo for short, has become an established field that, broadly speaking, seeks to understand how changes in development drive major transitions and innovation in organismal evolution. It does so via integrating the principles and methods of many subdisciplines of biology. Although we have gained unprecedented knowledge from the studies on model organisms in the past decades, many fundamental and crucially essential processes remain a mystery. Considering the tremendous biodiversity of our planet, the current model organisms seem insufficient for us to understand the evolutionary and physiological processes of life and its adaptation to exterior environments. The currently increasing genomic data and the recently available gene-editing tools make it possible to extend our studies to non-model organisms. In this review, we review the recent work on the regulatory signaling of developmental and regeneration processes, environmental adaptation, and evolutionary mechanisms using both the existing model animals such as zebrafish and Drosophila, and the emerging nonstandard model organisms including amphioxus, ascidian, ciliates, single-celled phytoplankton, and marine nematode. In addition, the challenging questions and new directions in these systems are outlined as well.

6.
Cell Tissue Res ; 385(1): 105-113, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33783606

RESUMO

Among vertebrates, urodele amphibians possess a unique ability to regenerate various body parts including limbs. However, reports of their digit regeneration remain scarce, especially information about the related genes. In this study, it was evident that matrix metalloproteinases (mmps) including mmp9, mmp3/10a, and mmp3/10b, which play a crucial role in tissue remodeling, are highly expressed during early stages of digit regeneration in axolotl. Using in situ hybridization, we revealed that wound epidermis and blastema are two major origins of the MMPs during the regeneration process. Additionally, we found that the inhibition of MMPs with GM6001 (a wide-spectrum inhibitor of MMPs) in vivo after amputation disturbed normal digit regeneration process and resulted in malformed regenerates. Furthermore, inhibition of MMPs hindered blastema formation and decreased cell apoptosis at early stages in the digit regenerates. All these points suggest that MMPs are required for digit regeneration, as they play a significant role in the regulation of blastema formation.

7.
Inorg Chem ; 59(19): 14337-14346, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-32940038

RESUMO

As increasing demand for noncontact temperature sensing, the development of a high-performance optical thermometer probe is more and more urgent. In this work, an efficient dual-mode optical thermometry strategy based on the Pr3+/Dy3+ energy transfer (ET) in some typical double-perovskite oxides is presented, which offers a promising way to design FIR/lifetime dual-mode optical thermometry with excellent temperature-measuring sensitivity and signal discrimination. According to this strategy, double-perovskite La2MgTiO6:Pr3+/Dy3+ phosphors are successfully synthesized. On the basis of diverse thermal responses between Pr3+ and Dy3+, the FIR of Pr3+ to Dy3+ (four FIR mode) in this material displays outstanding optical thermometry performance from 298 to 548 K. The maximum absolute and relative sensitivities (Sa and Sr) of mode 1 are 0.09 and 2.357% K-1, being better than the current optical temperature measurement materials. For the fluorescence lifetime mode, the Sa-max and Sr-max values reach 2.85 × s 10-4 and 1.814% K-1. Furthermore, the dual-mode optical thermometry mechanism was presented and studied. It also demonstrated excellent optical thermometry performance in the other Pr3+/Dy3+ codoped double-perovskite oxides, such as LaMg0.598Nb0.402O3, NaLa(MoO4)2, NaGd(MoO4)2, and NaLa(WO4)2, proving the universality of the presented strategy. This article presents an effective Pr3+/Dy3+ ET pathway for developing new and highly sensitive FIR/lifetime dual-mode optical temperature sensing materials.

8.
Inorg Chem ; 59(6): 3596-3605, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32105460

RESUMO

Full visible emission achieved by a single-phased system is of great interest to researchers for the development of high-quality solid-state lighting devices. Herein, novel Eu2+ and Mn2+ co-doped (1 - x)ß-Ca3(PO4)2-xCa9La(PO4)7 solid solution phosphors are designed to realize single-phased white light emission. The effects of variational x on lattice structure, color-tunable emission, thermal stability, and energy-transfer efficiency from Eu2+ to Mn2+ are systematically investigated. Tunable color emissions are achieved by manipulating the redistributions of Eu2+ ions among the different cationic sites under the influence of generated empty site in the M(4) site. Meanwhile, the changes of critical distances among the Eu2+ and Mn2+ caused by the variational x results in the changes of energy-transfer efficiency from different Eu2+ luminescent centers to Mn2+ due to the existence of structural confinement effect. The calculated results indicate that Eu1-Mn and Eu2-Mn possess higher energy-transfer efficiencies than other Eu-Mn pairs. Under the combined influence of the two effects, single-phased full visible white emission covering from 400 to 700 nm has been realized via the adjustment of solid solution, which makes the fabricated white-light-emitting diode (WLED) possess high color-rendering index (86.9) and R9 (87.2) as well as low correlated color temperature (3947 K). The results show that the 0.2ß-Ca3(PO4)2-0.8Ca9La(PO4)7:0.01Eu2+, 0.20Mn2+ could act as a promising phosphor for single-phased WLEDs. This work will open up a new avenue for tuning the multiple activator sites and energy-transfer efficiencies simultaneously to realize single-phased full visible white emission.

9.
J Agric Food Chem ; 67(43): 11994-12001, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31618578

RESUMO

Bioactivity-guided isolation of the endophytic fungus Fusarium sambucinum TE-6L residing in Nicotiana tabacum L. led to the discovery of two new angularly prenylated indole alkaloids (PIAs) with pyrano[2,3-g]indole moieties, amoenamide C (1) and sclerotiamide B (2), and four known biosynthetic congeners (3-6). Their structures were determined by comprehensive spectroscopic techniques, electronic circular dichroism (ECD), and X-ray diffraction. Compound 1 containing the bicyclo[2.2.2]diazaoctane core and indoxyl unit is rarely reported. All the compounds were evaluated for their antimicrobial and insecticidal activities. Notably, compounds 1-3 showed potent inhibitory effects against three human- and one plant-pathogenic bacterium, and seven plant-pathogenic fungi. Compounds 2-4 also exhibited remarkable larvicidal activity against first instar larvae of the cotton bollworm Helicoverpa armigera with mortality rates of 70.2%, 83.2%, and 70.5%, respectively. Further toxicity tests on zebrafish embryos were performed to evaluate the potential toxicity of PIAs. Of significance was that compound 3 in particular exhibited the highest activities but the lowest effects on the hatching of embryos among all the compounds. This study provides a basis for understanding developmental toxicity of PIAs exposure to zebrafish embryos, and also indicates the potential environmental risks of other natural compounds exposure in the aquatic ecosystem.


Assuntos
Anti-Infecciosos/química , Endófitos/química , Fusarium/química , Alcaloides Indólicos/química , Inseticidas/química , Animais , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Endófitos/isolamento & purificação , Fungos/efeitos dos fármacos , Fusarium/isolamento & purificação , Alcaloides Indólicos/metabolismo , Alcaloides Indólicos/farmacologia , Inseticidas/metabolismo , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Mariposas/efeitos dos fármacos , Tabaco/microbiologia , Peixe-Zebra/embriologia
10.
Development ; 146(4)2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30696711

RESUMO

Amphioxus, a cephalochordate, is an ideal animal in which to address questions about the evolution of regenerative ability and the mechanisms behind the invertebrate to vertebrate transition in chordates. However, the cellular and molecular basis of tail regeneration in amphioxus remains largely ill-defined. We confirmed that the tail regeneration of amphioxus Branchiostoma japonicum is a vertebrate-like epimorphosis process. We performed transcriptome analysis of tail regenerates, which provided many clues for exploring the mechanism of tail regeneration. Importantly, we showed that BMP2/4 and its related signaling pathway components are essential for the process of tail regeneration, revealing an evolutionarily conserved genetic regulatory system involved in regeneration in many metazoans. We serendipitously discovered that bmp2/4 expression is immediately inducible by general wounds and that expression of bmp2/4 can be regarded as a biomarker of wounds in amphioxus. Collectively, our results provide a framework for understanding the evolution and diversity of cellular and molecular events of tail regeneration in vertebrates.


Assuntos
Proteína Morfogenética Óssea 2/metabolismo , Proteína Morfogenética Óssea 4/metabolismo , Anfioxos/fisiologia , Regeneração , Transdução de Sinais , Cauda/fisiologia , Animais , Apoptose , Evolução Biológica , Biomarcadores/metabolismo , Proliferação de Células , Evolução Molecular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Filogenia , Análise de Sequência de RNA , Cicatrização
11.
Fish Shellfish Immunol ; 50: 21-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26796816

RESUMO

In fish, a series of maternal derived immune components have been identified in their eggs or embryos at very early stages, which are proposed to provide protections to themselves against pathogenic attacks from hostile environment. The phenomenon of maternal immunity has been also recorded in several invertebrate species, however, so far, very limited information about the maternal immune molecules are available. In this study, it was demonstrated maternal alpha2 macroglobulin (A2m) protein, an important innate immune factor, exists in the fertilized eggs of amphioxus Branchiostoma japonicum, an invertebrate chordate. Maternal mRNA of A2m was also detected in amphioxus embryos at very early developing stages. In addition, it was recorded that the egg lysate prepared from the newly fertilized eggs can inhibit the growth of both Gram-negative bacterium Escherichia coli and Gram-positive bacterium Staphylococcus aureus in a concentration dependent manner. The bacteriostatic activity can be reduced notably after precipitated A2m with anti-A2m antibody. Thus maternal A2m is partly attributed to the bacteriostatic activity. It was further demonstrated that recombinant A2m can bind to E. coli cells directly. All these points come to a result that A2m is a maternal immune factor existing in eggs of invertebrate chordate, which may be involved in defense their embryos against harmful microbes' attacks.


Assuntos
Imunidade Inata , Fatores Imunológicos/genética , Anfioxos/imunologia , alfa-Macroglobulinas/genética , Animais , Embrião não Mamífero/imunologia , Escherichia coli/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Fatores Imunológicos/metabolismo , Anfioxos/crescimento & desenvolvimento , Anfioxos/metabolismo , Anfioxos/microbiologia , Óvulo/imunologia , Staphylococcus aureus/fisiologia , alfa-Macroglobulinas/metabolismo
12.
Luminescence ; 31(1): 135-40, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26014423

RESUMO

BiPO4 and Eu-doped BiPO4 crystals were synthesized via a simple precipitation route at room temperature, employing Bi(NO3)3 and (NH4)2HPO4 as the reactants, Eu2O3 as the dopant and citric acid as a template. X-ray powder diffraction analyses showed that pure rhombohedral BiPO4 form was obtained, and was the preferential orientation growth of the crystal. Field emission scanning electron microscope observations showed that the concentration of Bi(3+) obviously changed the products' morphologies from nanosphere, hollow sphere to hexagonal prism. The acidity of the solution and the contents of citric acid and Eu(3+) ion tailored the size of the final crystals. Effects of concentration of Eu(3+) ion on the luminescence emission intensity were also investigated.


Assuntos
Bismuto/química , Európio/química , Luminescência , Nanoestruturas/química , Fosfatos/química
13.
PLoS One ; 7(3): e32392, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22427833

RESUMO

Serine protease inhibitors, or serpins, are a group of widely distributed proteins with similar structures that use conformational change to inhibit proteases. Antithrombin (AT) is a member of the serine protease inhibitor superfamily and a major coagulation inhibitor in all vertebrates, but its evolutionary origin remains elusive. In this study we isolated for the first time a cDNA encoding an antithrombin homolog, BjATl, from the protochordate Branchiostoma japonicum. The deduced protein BjATl consisted of 338 amino acids sharing 36.7% to 41.1% identity to known vertebrate ATs. BjATl contains a potential N-linked glycosylation site, two potential heparin binding sites and the reactive center loop with the absolutely conserved sequence Gly-Arg-Ser; all of these are features characteristic of ATs. All three phylogenetic trees constructed using Neighbor-Joining, Maximum-Likelihood and Bayesian-Inference methods also placed BjATl together with ATs. Moreover, BjATl expressed in yeast cells was able to inhibit bovine thrombin activity by forming a SDS-stable BjATl-thrombin complex. It also displays a concentration-dependent inhibition of thrombin that is accelerated by heparin. Furthermore, BjATl was predominantly expressed in the hepatic caecum and hind-gut, agreeing with the expression pattern of AT in mammalian species. All these data clearly demonstrate that BjATl is an ortholog of vertebrate ATs, suggesting that a primitive coagulation system emerged in the protochordate.


Assuntos
Proteínas Antitrombina/genética , Evolução Biológica , Coagulação Sanguínea/genética , Cordados não Vertebrados/química , Filogenia , Serpinas/genética , Animais , Proteínas Antitrombina/metabolismo , Sequência de Bases , Teorema de Bayes , Coagulação Sanguínea/fisiologia , Bovinos , Cordados não Vertebrados/fisiologia , DNA Complementar/genética , Funções Verossimilhança , Modelos Genéticos , Dados de Sequência Molecular , Análise de Sequência de DNA , Homologia de Sequência , Serpinas/metabolismo , Especificidade da Espécie , Trombina/metabolismo
14.
Fish Shellfish Immunol ; 31(6): 963-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21903171

RESUMO

Alpha-2 macroglobulin (α(2)M), a broad-spectrum protease inhibitor, exists widely in vertebrates and invertebrates, but little information is available to date regarding α(2)M in amphioxus, an animal bridging from invertebrates to vertebrates. Here we first show that the full α(2)M cDNA of Branchiostoma japonicum (Bjα(2)m) contained 5545 bp with an open reading frame of 4593 bp encoding signal sequence of 16 amino acid residues and a mature protein of 1514 residues. The calculated molecular mass and pI of mature Bjα(2)M were 164.2 kDa and 4.6 respectively. Bjα(2)m was mainly expressed in the hepatic caecum and hind-gut in a tissue-specific manner, contrasting to the primary expression of α(2)M in vertebrate liver. Following challenge with lipopolysaccharide (LPS), Bjα(2)m expression was significantly up-regulated (7-folds) at 8 h and then declined to the base line at 16 h. Taken together, it is suggested that Bjα(2)M is an immune-relevant molecule possibly involved in the acute phase response via the digestive organs.


Assuntos
Cordados não Vertebrados/genética , Regulação da Expressão Gênica/imunologia , Filogenia , alfa-Macroglobulinas/genética , Reação de Fase Aguda/imunologia , Animais , Sequência de Bases , Northern Blotting , Clonagem Molecular , Análise por Conglomerados , Primers do DNA/genética , DNA Complementar/genética , Trato Gastrointestinal/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hibridização In Situ , Lipopolissacarídeos/farmacologia , Fígado/metabolismo , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA
15.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 26(5): 992-5, 2009 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-19947475

RESUMO

As there is justification showing that Poiseuille's Law is not suited for vertical Capillary tube viscometer, Poiseuille's Law has not been used to deduce the calculation formula for measuring liquid viscosity by means of vertical Capillary tube viscometer; it can only be used to deduce the calculation formula for measuring liquid viscosity by horizontal capillary tube viscometer. In this article, we explained the extension of Poiseuille's Law to deduce the Calculation formula for measuring liquid viscosity by using shallow pool and deep pool Capillar tube viscometer, and so corrected the mistakes in using Poiseuille's Law for a long time.


Assuntos
Viscosidade Sanguínea , Testes Hematológicos/instrumentação , Hemorreologia , Humanos
16.
Cell Tissue Res ; 338(1): 67-77, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19657677

RESUMO

The growth hormone (GH)/insulin-like growth factor (IGF) axis is unique to all the vertebrate species but its evolutionary origin is ill-defined. We therefore cloned a cDNA encoding Branchiostoma belcheri IGF (BbIGF). BbIGF was expressed in a tissue-specific manner, with the most abundant expression in the hepatic caecum, the putative liver precursor. The recombinant BbIGF expressed in vitro showed mitogenic activity capable of stimulating cell proliferation in the flounder gill, a characteristic of vertebrate IGF. Quantitative real-time polymerase chain reaction demonstrated that the recombinant rat GH was able to induce a significant up-regulation of BbIGF expression in the hepatic caecum. Moreover, Western blotting revealed the presence of a molecule similar to rat GH receptor in the hepatic caecum. These results suggest that BbIGF expression is inducible by exogenous mammalian GH, suggesting the presence of a GH/IGF axis in B. belcheri. The relationship between BbIFG expression and the origin of the vertebrate liver is discussed.


Assuntos
Cordados/metabolismo , Hormônio do Crescimento/metabolismo , Mitose/fisiologia , Somatomedinas/metabolismo , Sequência de Aminoácidos , Animais , DNA Complementar/genética , DNA Complementar/metabolismo , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Filogenia , Conformação Proteica , Isoformas de Proteínas/química , Isoformas de Proteínas/classificação , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Ratos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Somatomedinas/química , Somatomedinas/classificação , Somatomedinas/genética
17.
PLoS One ; 4(1): e4234, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19156196

RESUMO

BACKGROUND: The eggs in most invertebrates are fertilized externally, and therefore their resulting embryos are exposed to an environment full of microbes, many of which are pathogens capable of killing other organisms. How the developing embryos of invertebrates defend themselves against pathogenic attacks is an intriguing question to biologists, and remains largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here we clearly demonstrated that the egg cytosol prepared from the newly fertilized eggs of amphioxus Branchiostoma belcheri, an invertebrate chordate, was able to inhibit the growth of both the Gram-negative bacterium Vibrio anguillarum and the Gram-positive bacterium Staphylococcus aureus. All findings point to that it is the complement system operating via the alternative pathway that is attributable to the bacteriostatic activity. CONCLUSIONS/SIGNIFICANCE: This appears to be the first report providing the evidence for the functional role of the maternal complement components in the eggs of invertebrate species, paving the way for the study of maternal immunity in other invertebrate organisms whose eggs are fertilized in vitro. It also supports the notion that the early developing embryos share some defense mechanisms common with the adult species.


Assuntos
Cordados/metabolismo , Citosol/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Óvulo/microbiologia , Animais , Ativação do Complemento , Complemento C3/metabolismo , Fator B do Complemento/metabolismo , Proteínas do Sistema Complemento/metabolismo , Citosol/imunologia , Humanos , Fatores Imunológicos/metabolismo , Modelos Biológicos , Óvulo/imunologia , Óvulo/metabolismo , Staphylococcus aureus/metabolismo , Vibrio/metabolismo
18.
Fish Shellfish Immunol ; 26(2): 235-42, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19063974

RESUMO

Tachylectin-related proteins have been identified in various organisms from slime molds to sponges to bony fish, yet little is known to date about it in protochordate amphioxus, an important organism occupying a nodal position from invertebrates to vertebrates. Moreover, if the protein acts as an immune-relevant molecule remains controversial. Here we demonstrated the presence of a tachylectin-related gene in Branchiostoma belcheri. The predicted gene product, termed BbTL, consists of 305 amino acids with a putative N-terminal signal peptide and 6 tachylectin-typical tandem repeats of 30-33 amino acids. In situ hybridization histochemistry indicates a tissue-specific expression pattern of BbTL in adult amphioxus with the most abundant expression in the hepatic caecum and hind-gut. Quantitative real-time PCR reveals that challenge with LPS results in a significant up-regulation of BbTL expression in the guts. In addition, the recombinant BbTL expressed in Pichia pastoris is able to inhibit the growth of Gram-negative bacterium Escherichia coli in a dose-dependent manner. All these suggest that BbTL, like most other tachylectin-related proteins, is involved in the host immune defense, and the digestive system of B. belcheri appears the major immune tissue responding to LPS challenge.


Assuntos
Cordados/genética , Cordados/imunologia , Regulação da Expressão Gênica , Lectinas/genética , Lectinas/imunologia , Proteínas Recombinantes/imunologia , Adjuvantes Imunológicos/farmacologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Escherichia coli/fisiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Lectinas/química , Lipopolissacarídeos/farmacologia , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Staphylococcus aureus/fisiologia
19.
DNA Seq ; 17(2): 122-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17076254

RESUMO

An amphioxus cDNA, AmphiGM2AP, encoding GM2 activator protein was isolated from the gut cDNA library of Branchiostoma belcheri. It is 907 bp long, and its longest open reading frame codes for a precursor protein consisting of 242 amino acid residues with a signal peptide of 14 amino acids. The deduced amino acid sequence includes a conserved domain typical of GM2APs between residues 53 and 224, a single N-linked glycosylation site at position 65 and 8 conserved cysteines. Phylogenetic analysis showed that amphiGM2AP forms a club together with invertebrate GM2APs, indicating that AmphiGM2AP is evolutionarily closely related to invertebrate GM2APs rather than vertebrate ones. Both Northern blotting and in situ hybridization histochemistry analyses revealed a tissue-specific expression pattern of AmphiGM2AP in adult amphioxus with the strongest expression in the digestive system, which is in contrast to the widespread expression pattern of human, mouse and sheep GM2AP genes. It is suggested that AmphiGM2AP is possibly involved in the take-in of digested food components like lipid molecules.


Assuntos
Cordados não Vertebrados/genética , Proteína Ativadora de G(M2)/genética , Regulação da Expressão Gênica , Sequência de Aminoácidos , Animais , Sequência de Bases , Proteína Ativadora de G(M2)/química , Perfilação da Expressão Gênica , Biblioteca Gênica , Dados de Sequência Molecular , Alinhamento de Sequência
20.
J Biochem Mol Biol ; 39(5): 511-5, 2006 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-17002870

RESUMO

Alanine aminotransferase (AAT) is mainly synthesized in the liver, and its level in mammalian serum is elevated after acute phase induction. Here we demonstrated that sheep anti-human AAT antibody cross-reacted with amphioxus humoral fluids as well as human serum; and the concentration of AAT in the humoral fluids in amphioxus increased after the acute challenge with lipopolysaccharide, while the level of total proteins remains unchanged. These suggest the presence of the same acute phase response pattern in amphioxus, as observed in some mammalian species. Immunohistochemically, AAT was localized in the hepatic diverticulum, ovary and testis. It appears that the hepatic diverticulum in amphioxus is functionally homologous to the vertebrate liver in respect of AAT synthesis, supporting the hypothesis that the vertebrate liver evolved from the hepatic diverticulum of an amphioxus-like ancestor during early chordate evolution.


Assuntos
Alanina Transaminase/metabolismo , Cordados não Vertebrados/enzimologia , Cordados não Vertebrados/imunologia , Lipopolissacarídeos/imunologia , Reação de Fase Aguda , Alanina Transaminase/imunologia , Animais , Western Blotting , Reações Cruzadas , Eletroforese em Gel de Poliacrilamida , Humanos , Regulação para Cima
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