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1.
J Neurochem ; 166(4): 720-746, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37337846

RESUMO

Krabbe disease is an inherited demyelinating disease caused by a genetic deficiency of the lysosomal enzyme galactosylceramide (GalCer) ß-galactosidase (GALC). The Twitcher (Twi) mouse is a naturally occurring, genetically and enzymatically authentic mouse model that mimics infantile-onset Krabbe disease. The major substrate for GALC is the myelin lipid GalCer. However, the pathogenesis of Krabbe disease has long been explained by the accumulation of psychosine, a lyso-derivative of GalCer. Two metabolic pathways have been proposed for the accumulation of psychosine: a synthetic pathway in which galactose is transferred to sphingosine and a degradation pathway in which GalCer is deacylated by acid ceramidase (ACDase). Saposin-D (Sap-D) is essential for the degradation of ceramide by ACDase in lysosome. In this study, we generated Twi mice with a Sap-D deficiency (Twi/Sap-D KO), which are genetically deficient in both GALC and Sap-D and found that very little psychosine accumulated in the CNS or PNS of the mouse. As expected, demyelination with the infiltration of multinucleated macrophages (globoid cells) characteristic of Krabbe disease was milder in Twi/Sap-D KO mice than in Twi mice both in the CNS and PNS during the early disease stage. However, at the later disease stage, qualitatively and quantitatively comparable demyelination occurred in Twi/Sap-D KO mice, particularly in the PNS, and the lifespans of Twi/Sap-D KO mice were even shorter than that of Twi mice. Bone marrow-derived macrophages from both Twi and Twi/Sap-D KO mice produced significant amounts of TNF-α upon exposure to GalCer and were transformed into globoid cells. These results indicate that psychosine in Krabbe disease is mainly produced via the deacylation of GalCer by ACDase. The demyelination observed in Twi/Sap-D KO mice may be mediated by a psychosine-independent, Sap-D-dependent mechanism. GalCer-induced activation of Sap-D-deficient macrophages/microglia may play an important role in the neuroinflammation and demyelination in Twi/Sap-D KO mice.


Assuntos
Leucodistrofia de Células Globoides , Camundongos , Animais , Leucodistrofia de Células Globoides/genética , Leucodistrofia de Células Globoides/patologia , Saposinas/genética , Psicosina/metabolismo , Galactosilceramidase/genética , Galactosilceramidase/metabolismo , Modelos Animais de Doenças
2.
Anal Chem ; 95(32): 11868-11873, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37535807

RESUMO

Protein glycosylation is a crucial factor that must be evaluated in biological pharmaceuticals. The glycoform profile of a protein can vary depending on the conditions of the cultivation, purification process, and the selection of a host cell. Lectin microarrays are reliable bioanalytical methods used in the early phases of bioprocesses for the detection of glycosylation. The concept of a fully automated glycan detection with a bead array has been previously reported; however, no simple system has been constructed on fluorescence-based detection using a microarray. Here, we present a fully automated detection system equipped with a novel fluorescence detector for a 13-lectin bead array with a single tip. The lattice-like arrangement of a set of fibers proximate to the tip of the light emitting diode and photomultiplier tube detector minimized the noise caused by the reflection of incident light on the plastic capillary tip and bead. A unique rolling-circle fiber unit with quadruple lattices stacked in two layers realizes the 8-parallel automeasurement with a drastic reduction in scanning time and machine size. The 8-glycan profiles obtained automatically within 25 min were identical with those obtained with the conventional lectin microarray after overnight incubation. The signals obtained were represented as lectin dotcodes. Therefore, autolectin dotcoding assisted by the twin 8 legs named as "detection and irradiation octopuses" may be a rapid glyco-evaluation system during the production and development of biopharmaceuticals.

3.
Age Ageing ; 51(3)2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35258518

RESUMO

Fat embolism syndrome (FES) is a rare condition characterised by the classic triad of respiratory distress, neurologic symptoms and petechial rash. Here, we encountered a case of FES in a patient with an asymptomatic right undisplaced femoral neck fracture (Garden Stage II). FES was diagnosed based on the Gurd and Willson's diagnostic criteria and brain magnetic resonance imaging features. To the best of our knowledge, this is the first case of FES in a patient with an undisplaced femoral neck fracture. This study highlights the importance of considering the possibility of FES even in patients with undisplaced femoral neck fractures.


Assuntos
Embolia Gordurosa , Fraturas do Colo Femoral , Encéfalo , Embolia Gordurosa/diagnóstico por imagem , Embolia Gordurosa/etiologia , Fraturas do Colo Femoral/complicações , Fraturas do Colo Femoral/diagnóstico por imagem , Fraturas do Colo Femoral/cirurgia , Fixação Interna de Fraturas , Humanos , Imageamento por Ressonância Magnética
4.
J Appl Toxicol ; 41(9): 1390-1399, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33336402

RESUMO

The G protein-coupled estrogen receptor 1 (Gper1) is a membrane-bound estrogen receptor that mediates non-genomic action of estrogens. A Gper1-mediating pathway has been implicated in reproductive activities in fish, including oocyte growth, but Gper1 has been characterized in only a very limited number of fish species. In this study, we cloned and characterized two genes encoding medaka (Oryzias latipes) Gper1s, namely, Gper1a and Gper1b, and phylogenic and synteny analyses suggest that these genes originate through a teleost-specific whole genome duplication event. We found that Gper1a induced phosphorylation of mitogen-activated protein kinase (MAPK) in 293T cells transfected with medaka Gper1s on exposure to the natural estrogen, 17ß-estradiol (E2) and a synthetic Gper1 agonist (G-1), and treatment with both E2 and G-1 also decreased the rate of spontaneous maturation in medaka oocytes. These findings show that the processes for oocyte growth and maturation are sensitive to estrogens and are possibly mediated through Gper1a in medaka. We also show that 17α-ethinylestradiol (EE2), one of the most potent estrogenic endocrine-disrupting chemicals, and bisphenol A (BPA, a weak environmental estrogen) augmented phosphorylation of MAPK through medaka Gper1s in 293T cells. Interestingly, however, treatment with EE2 or BPA did not attenuate maturation of medaka oocytes. Our findings support that Gper1-mediated effects on oocytes are conserved among fish species, but effects of estrogenic endocrine-disrupting chemicals on oocytes acting through Gper1 may be divergent among fish species.


Assuntos
Oryzias/metabolismo , Receptores de Estrogênio/genética , Receptores Acoplados a Proteínas G/genética , Animais , Compostos Benzidrílicos/farmacologia , Disruptores Endócrinos/farmacologia , Estradiol/metabolismo , Etinilestradiol/metabolismo , Feminino , Peixes , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Fenóis/farmacologia , Fosforilação , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismo , Especificidade da Espécie
5.
Arch Biochem Biophys ; 668: 29-38, 2019 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-31071303

RESUMO

Ca2+/calmodulin-dependent protein kinase I isoforms (CaMKIα, ß, γ, and δ) play important roles in Ca2+ signaling in eukaryotic cells by being activated by CaMK kinase (CaMKK) through phosphorylation at a Thr residue in the activation loop. However, we have recently found that, unlike rat CaMKIα (rCaMKIα), C-terminally truncated fragments of zebrafish and mouse CaMKIδ [zCaMKIδ(1-299) and mCaMKIδ(1-297)] produced by Escherichia coli exhibit almost full activity in the absence of CaMKK. To address the CaMKK-independent activation mechanism of CaMKIδ in E. coli cells, here we performed comparative analyses between recombinant zCaMKIδ(1-299) and rCaMKIα(1-294) in vitro. By using a kinase-dead mutant of zCaMKIδ(1-299) and λ phosphatase coexpression method, we elucidated that zCaMKIδ(1-299) was highly autophosphorylated and activated in E. coli during cell culture, but rCaMKIα(1-294) was not. The major autophosphorylation site leading to activation of the kinase was Ser296, determined using mass spectrometry analysis in conjunction with site-directed mutagenesis. Furthermore, mimicking phosphorylation at Ser296 in full-length zCaMKIδ resulted in additional activation of the kinase compared with CaMKI fully activated by CaMKK. Our results provide the first evidence that CaMKIδ is activated through CaMKK-independent phosphorylation at Ser296, which might be a clue to understand the physiological regulation of CaMKIδ isoform.


Assuntos
Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina/metabolismo , Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina/metabolismo , Ativação Enzimática/fisiologia , Proteínas de Peixe-Zebra/metabolismo , Sequência de Aminoácidos , Animais , Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina/química , Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina/genética , Escherichia coli/enzimologia , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Camundongos Endogâmicos BALB C , Mutagênese Sítio-Dirigida , Mutação , Fosforilação , Processamento de Proteína Pós-Traducional , Ratos , Alinhamento de Sequência , Serina/química , Peixe-Zebra , Proteínas de Peixe-Zebra/química , Proteínas de Peixe-Zebra/genética
6.
J Vis Exp ; (208)2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-39007607

RESUMO

Protein glycosylation, a critical post-translational modification, influences the stability, efficacy, and immunogenicity of recombinant proteins, including biopharmaceuticals. Glycan structures exhibit significant heterogeneity, varying with production cell types, culture conditions, and purification methods. Consequently, monitoring and evaluating the glycan structures of recombinant proteins is vital, particularly in biopharmaceutical production. The lectin microarray, a technique complementary to mass spectrometry, boasts high sensitivity and ease of use. However, it typically requires more than a day to yield results. To adapt it to non-glycoscience research or drug product process development, an automated, high-throughput alternative is needed. Therefore, the world's first fully automated lectin-based glycan profiling system was developed, utilizing the "bead array in a single tip (BIST)" technology concept. This system allows for the preparation and storage of lectin-immobilized beads in units of 1,000, with customizable parallel insertion orders for various purposes. This article presents a practical protocol for research involving "glyco-qualified" recombinant proteins. After testing their reactivity against 12 polyacrylamide-glycan conjugates, 15 lectins were selected to increase the system's versatility. In addition, the sample labeling process was optimized by switching from Cy3 to biotin, reducing the overall processing time by 30 min. For immediate data qualification, lectin-binding signals are displayed as a dotcode on the top monitor. The system's reliability was confirmed through day-to-day reproducibility tests, repeatability tests, and long-term storage tests, with a coefficient of variation of <10%. This user-friendly and rapid glyco-analyzer has potential applications in the quality monitoring of endogenous glycoproteins for biomarker evaluation and validation. This method facilitates analysis for those new to glycoscience, thereby broadening its practical utility.


Assuntos
Lectinas , Polissacarídeos , Proteínas Recombinantes , Proteínas Recombinantes/química , Polissacarídeos/química , Polissacarídeos/análise , Lectinas/química , Glicosilação , Automação Laboratorial/métodos
7.
J Gastrointest Oncol ; 13(2): 885-897, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35557564

RESUMO

Background and Objective: Borderline resectable pancreatic cancer (BRPC) is a tumor that infiltrates into the large blood vessels, with a high probability that the tumor will remain after surgical resection. To date, there has been no confirmed treatment strategy for BRPC. However, high-level studies, such as those using the intention-to-treat analysis, have recently been published. This review aimed to update the current status of treatment strategies for BRPC. Methods: We searched for studies, including those investigating patients with BRPC, either treated by upfront surgery or with neoadjuvant treatment and reported the R0 resection rate and overall survival using an intention-to-treat analysis. Key Content and Findings: Consequently, 22 articles were identified. Twelve were prospective studies. Six studies compared neoadjuvant therapy with upfront surgery, and both the R0 resection rate and overall survival in patients who underwent upfront surgery were significantly worse than in those who underwent neoadjuvant treatment in all studies. Six studies evaluated neoadjuvant chemotherapy, while 15 studies neoadjuvant chemoradiation. No reports showed the superiority or inferiority of the two methods, and the optimal regimen was not determined in either treatment. The high-precision radiation therapy techniques have been studied, but the optimal method and dose fractionation were unclear. Conclusions: The current standard of care for the BRPC is neoadjuvant therapy. Although the optimal regimen of neoadjuvant therapy was not determined, several prospective trials are underway to identify the optimal neoadjuvant treatment.

8.
Rinsho Shinkeigaku ; 61(8): 563-566, 2021 Aug 30.
Artigo em Japonês | MEDLINE | ID: mdl-34275957

RESUMO

A 50-year-old man with mitral regurgitation presented with right frontal subcortical hemorrhage. Although he had no fever and his white blood cell count was in the normal range, CT angiography demonstrated a micro cerebral aneurysm, and all three blood cultures were positive for Staphylococcus warneri (S. warneri). Thus, we diagnosed him with infective endocarditis. His condition improved successfully by immediate antibiotics and cerebral aneurysm clipping. S. warneri is a member of coagulase-negative staphylococci that are low-virulence and resident flora of the skin. S. warneri rarely causes infective endocarditis on native valves. Infective endocarditis caused by S. warneri manifests insidious course without inflammatory reactions such as fever and leukocytosis, and thus, diagnosis can be delayed. Attention should be paid to a patient who develops subcortical hemorrhage without a history of hypertension or inflammatory reactions as in this case.


Assuntos
Endocardite Bacteriana , Aneurisma Intracraniano , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/etiologia , Endocardite Bacteriana/complicações , Febre/etiologia , Humanos , Inflamação , Leucocitose/etiologia , Masculino , Pessoa de Meia-Idade , Staphylococcus
9.
J Biochem ; 169(4): 445-458, 2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33417706

RESUMO

Ca2+/calmodulin (CaM)-dependent protein kinase Iδ (CaMKIδ) is a Ser/Thr kinase that plays pivotal roles in Ca2+ signalling. CaMKIδ is activated by Ca2+/CaM-binding and phosphorylation at Thr180 by CaMK kinase (CaMKK). In this study, we characterized four splice variants of mouse CaMKIδ (mCaMKIδs: a, b, c and d) found by in silico analysis. Recombinant mCaMKIδs expressed in Escherichia coli were phosphorylated by CaMKK; however, only mCaMKIδ-a and c showed protein kinase activities towards myelin basic protein in vitro, with mCaMKIδ-b and mCaMKIδ-d being inactive. Although mCaMKIδ-a and mCaMKIδ-c underwent autophosphorylation in vitro, only mCaMKIδ-c underwent autophosphorylation in 293T cells. Site-directed mutagenesis showed that the autophosphorylation site is Ser349, which is found in the C-terminal region of only variants c and b (Ser324). Furthermore, phosphorylation of these sites (Ser324 and Ser349) in mCaMKIδ-b and c was more efficiently catalyzed by cAMP-dependent protein kinase in vitro and in cellulo as compared to the autophosphorylation of mCaMKIδ-c. Thus, variants of mCaMKIδ possess distinct properties in terms of kinase activities, autophosphorylation and phosphorylation by another kinase, suggesting that they play physiologically different roles in murine cells.


Assuntos
Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina , Animais , Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina/química , Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina/genética , Proteína Quinase Tipo 1 Dependente de Cálcio-Calmodulina/metabolismo , Linhagem Celular , AMP Cíclico/genética , AMP Cíclico/metabolismo , Humanos , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Camundongos , Fosforilação , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
10.
Curr Protoc Protein Sci ; 99(1): e103, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32073758

RESUMO

Lectin is a biomolecule that recognizes a specific part of glycans and, thus, has been used widely as a probe for glycoprotein analysis. Owing to the wide repertoire in nature combined with the recent two decades of advances in microarray technology, the multiplexed use of lectins has been widely used for glycan profiling of endogenous proteins. Because protein glycosylation is recognized as being biologically important and is expected to be a reliable disease marker, lectin microarray analysis with highly sensitive detection has been used to discover disease-relevant glycosylation alterations. However, the conventional system is limited to research purposes; thus, its implementation in clinical settings is warranted. Here, we provide an automatic glycan profiling method using GlycoBIST. A unique array format is used for 10-plexed lectin-glycoprotein interaction analysis on 1-mm-sized beads, which are arranged vertically in a capillary-shaped plastic tip. Using a one-boxed autopipetting machine, the whole process (including interaction, washing, and detection) is performed automatically and serially, resulting in reproducible measurements. In this article, a typical method for glycan profiling of a purified glycoprotein and the fabrication of GlycoBIST tips is explained. © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Fabrication of a GlycoBIST tip Basic Protocol 2: Automatic profiling of a target glycoprotein using GlycoBIST.


Assuntos
Glicoproteínas/análise , Lectinas/química , Análise Serial de Proteínas , Glicoproteínas/metabolismo , Glicosilação
11.
Food Res Int ; 116: 883-887, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30717019

RESUMO

Aroma release kinetics determines the palatability of food consumed by humans. Therefore, to estimate release behaviors of aroma compounds is important. We investigated the relationship between the rates of the release of aroma compounds from food matrices and octanol-water, octanol-air, and water-air partition coefficients. The aroma compounds used were limonene, ethyl hexanoate, 2-methylpyrazine, nonanal, benzaldehyde, ethyl benzoate, α-terpineol, geraniol, benzyl alcohol, and octanoic acid. The rates of their release from oil-in-water (O/W) emulsions were measured under non-equilibrium conditions using a purge-and-trap dynamic headspace extraction system. The results indicated that the octanol-air partition coefficients correlated better with the logarithms of the aroma compound release rates than either the octanol-water or the water-air partition coefficients. Furthermore, this correlation was independent of the oil volume ratios in the O/W emulsions. Our findings therefore suggest that octanol-air partition coefficients can be used to predict the release rates of aroma compounds from O/W emulsions.


Assuntos
Ar , Análise de Alimentos/métodos , Octanóis/química , Odorantes/análise , Óleos/química , Olfato , Água/química , Emulsões , Cinética
12.
Chem Sci ; 10(25): 6245-6253, 2019 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-31367299

RESUMO

A polymerizable amphiphile having two zwitterionic head-groups has been designed. This compound co-organizes with an acid, bis(trifluoromethanesulfonyl)imide (HTf2N), into a gyroid bicontinuous cubic liquid-crystalline phase. In situ polymerization of this phase has been successfully achieved by UV irradiation in the presence of a photoinitiator, yielding a self-standing gyroid-nanostructured polymer film. When the polymer film is placed under different relative humidity conditions or in water, it absorbs water owing to the strong hydration ability of the zwitterionic parts. It has been found that the polymer film preserves the gyroid nanostructure after the water absorption. Based on reconstructed electron density maps, it is assumed that the absorbed water molecules form a 3D continuous network along the gyroid minimal surface, which satisfies several key conditions for inducing fast proton conduction. As expected, such hydrated films show high ionic conductivities in the order of 10-1 S cm-1 when the water content of the film reaches 15.6 wt% at RH = 90%. The high conductivity is attributed to the induction of the Grotthuss mechanism, that is, proton conduction via the hydrogen-bonding network of the incorporated water molecules.

13.
Sci Rep ; 7(1): 17873, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29259295

RESUMO

Heterothallic strains of the Closterium peracerosum-strigosum-littorale (C. psl.) complex have two sexes, mating-type plus (mt+) and mating-type minus (mt-). Conjugation between these two sexes is regulated by two sex pheromones, protoplast-release-inducing protein (PR-IP) and PR-IP Inducer, which are produced by mt+ and mt- cells, respectively. PR-IP mediates the release of protoplasts from mt- cells during mating. In this study, we examined the mechanism of action of CpRLP1 (receptor-like protein 1), which was previously identified in a cDNA microarray analysis as one of the PR-IP-inducible genes. Using CRISPR/Cas9 technology, we generated CpRLP1 knockout mutants in mt- cells of the C. psl. complex. When the knockout mt- cells were mixed with wild-type mt+ cells, conjugation was severely reduced. Many cells released protoplasts without pairing, suggesting a loss of synchronization between the two mating partners. Furthermore, the knockout mutants were hypersensitive to PR-IP. We conclude that CpRLP1 is a negative regulator of PR-IP that regulates the timing of protoplast release in conjugating C. psl. cells. As the first report of successful gene knockout in the class Charophyceae, this study provides a basis for research aimed at understanding the ancestral roles of genes that are indispensable for the development of land plants.


Assuntos
Proteínas de Arabidopsis/genética , Sistemas CRISPR-Cas/fisiologia , Proteínas de Transporte/genética , Closterium/fisiologia , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Reprodução/fisiologia , Atrativos Sexuais/fisiologia , Sequência de Aminoácidos , Fenômenos Biológicos/genética , Sistemas CRISPR-Cas/genética , Closterium/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/fisiologia , Técnicas de Inativação de Genes/métodos , Protoplastos/fisiologia , Reprodução/genética , Atrativos Sexuais/genética
14.
Anim Sci J ; 88(10): 1629-1635, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28402026

RESUMO

The aim of this study was to evaluate the influence of rider's skill on the plasma cortisol levels of trekking horses on two courses, walking on field and forest courses (about 4.5 to 5.1 km each). Three riders of different skills did horse trekking (HT) in a tandem line under a fixed order: advanced-leading, beginner-second and intermediate-last. A total of six horses were used and they experienced all positions in both courses; a total of 12 experiments were done. Blood samples were obtained before HT, immediately after and 2 h after HT. As a control, additional blood samples were obtained from the same horses on non-riding days. Irrespective of the course and the rider's skill, the cortisol level before HT was higher than that of control (P < 0.05). In both courses, the cortisol levels immediately after HT ridden by the advanced rider were higher than that of control (P < 0.05). However, in every case, the cortisol level 2 h after HT was closely similar to the level of the control. Thus, we concluded the stress of trekking horse was not sufficient to disturb the circadian rhythm of the cortisol level, irrespective of the course and the rider's skill.


Assuntos
Florestas , Marcha/fisiologia , Cavalos/fisiologia , Cavalos/psicologia , Vínculo Humano-Animal , Hidrocortisona/sangue , Destreza Motora/fisiologia , Esportes/fisiologia , Estresse Psicológico/sangue , Estresse Psicológico/fisiopatologia , Atletismo , Animais , Ritmo Circadiano/fisiologia , Humanos , Fatores de Tempo
15.
Chem Commun (Camb) ; 52(82): 12167-12170, 2016 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-27711468

RESUMO

Gemini amphiphilic zwitterions exhibit thermotropic bicontinuous cubic liquid-crystalline phases having a 3D continuous ionic domain. Incorporation of an acid into the materials led to the creation of novel electrolytes transporting protons efficiently through the 3D continuous domain.

16.
J Biochem ; 157(5): 345-56, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25433861

RESUMO

The aim of this study was to determine the physiological role of skin lectins of the Japanese bullhead shark (Heterodontus japonicus). A skin extract was subjected to affinity chromatography using seven different sugars as ligands. Molecular mass and N-terminal amino acid sequence analyses indicated elution of the same protein by each of the seven respective cognate ligands from sugar affinity columns. The predicted amino acid sequence encoded by the cDNA of this protein [designated as H. japonicus C-type-lectin (HjCL)] identified it as a novel fish subgroup VII C-type lectin evolutionarily related to snake venom lectins. HjCL was predicted to bind to mannose because of the presence of a Glu-Pro-Asn (EPN) motif; however, haemagglutination inhibition assays and glycoconjugate microarray analysis demonstrated its binding to numerous structurally diverse sugars. Competitive sugar-binding assays using affinity chromatography indicated that HjCL bound multiple sugars via a common carbohydrate-recognition domain. The mRNA encoding HjCL was specifically detected in the skin, and immunohistochemical analysis detected its expression in uncharacterized large cells in the epidermis. HjCL agglutinated the bacterial pathogen Edwardsiella tarda and promoted immediate clotting of shark blood, indicating that HjCL is involved in host defence on the skin surface especially when the shark is injured and bleeds.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Metabolismo dos Carboidratos , Lectinas Tipo C/isolamento & purificação , Pele/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Testes de Hemaglutinação , Lectinas Tipo C/química , Lectinas Tipo C/metabolismo , Dados de Sequência Molecular , Filogenia , Ligação Proteica , Tubarões
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