RESUMO
Total RNA from lipopolysaccharide (LPS)-stimulated rat macrophages used to treat protoplasts from an Aspergillus nidulans strain originated the RT2 regenerated strain, whose culture supernatant showed anti-inflammatory activity in Wistar rats. The protein fraction presenting such anti-inflammatory activity was purified and biochemically identified. The screening of the fraction responsible for such anti-inflammatory property was performed by evaluating the inhibition of carrageenan-induced paw edema in male Swiss mice. Biochemical analyses of the anti-inflammatory protein used chromatography, carbohydrates quantification of the protein sample, amino acids content analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Total sugar quantification revealed 32 percent glycosylation of the protein fraction. Amino acid analysis of such fraction showed a peculiar pattern presenting 29 percent valine. SDS-PAGE revealed that the protein sample is pure and its molecular weight is about 40kDa. Intravenous injection of the isolated substance into mice significantly inhibited carrageenan-induced paw edema. The isolated glycoprotein decreased carrageenan-induced paw edema in a prostaglandin-dependent phase, suggesting an inhibitory effect of the isolated glycoprotein on prostaglandin synthesis.
Assuntos
Camundongos , Animais , Anti-Inflamatórios , Aspergillus nidulans , Aspergilose , GlicoproteínasRESUMO
A novel family of proteins with kininogenase activity and unique primary structure was characterized using combined pharmacological, proteomic and transcriptomic approaches of Thalassophryne nattereri fish venom. The major venom components were isolated and submitted to bioassays corresponding to its main effects: nociception and edema. These activities were mostly located in one fraction (MS3), which was further fractionated. The isolated protein, named natterin, was able to induce edema, nociception and cleave human kininogen and kininogen-derived synthetic peptides, releasing kallidin (Lys-bradykinin). The enzymatic digestion was inhibited by kallikrein inhibitors as Trasylol and TKI. Natterin N-terminal peptide showed no similarity with already known proteins present in databanks. Primary structure of natterin was obtained by a transcriptomic approach using a representative cDNA library constructed from T. nattereri venom glands. Several expressed sequence tags (ESTs) were obtained and processed by bioinformatics revealing a major group (18%) of related sequences unknown to gene or protein sequence databases. This group included sequences showing the N-terminus of isolated natterin and was named Natterin family. Analysis of this family allowed us to identify five related sequences, which we called natterin 1-4 and P. Natterin 1 and 2 sequences include the N-terminus of the isolated natterin. Furthermore, internal peptides of natterin 1-3 were found in major spots of whole venom submitted to mass spectrometry/2DGE. Similarly to the ESTs, the complete sequences of natterins did not show any significant similarity with already described tissue kallikreins, kininogenases or any proteinase, all being entirely new. These data present a new task for the knowledge of the action of kininogenases and may help in understanding the mechanisms of T. nattereri fish envenoming, which is an important medical problem in North and Northeast of Brazil.
Assuntos
Batracoidiformes/metabolismo , Venenos de Peixe/isolamento & purificação , Calicreínas/isolamento & purificação , Sequência de Aminoácidos , Animais , Sequência de Bases , Cromatografia em Gel , Eletroforese em Gel Bidimensional , Venenos de Peixe/química , Peixes Venenosos , Biblioteca Gênica , Calicreínas/química , Dados de Sequência Molecular , Alinhamento de SequênciaRESUMO
A novel family of proteins with kininogenase activity and unique primary structure was characterized using combined pharmacological, proteomic and transcriptomic approaches of Thalassophryne nattereri fish venom. The major venom components were isolated and submitted to bioassays corresponding to its main effects: nociception and edema. These activities were mostly located in one fraction (MS3), which was further fractionated. The isolated protein, named natterin, was able to induce edema, nociception and cleave human kininogen and kininogen-derived synthetic peptides, releasing kallidin (Lys-bradykinin). The enzymatic digestion was inhibited by kallikrein inhibitors as Trasylol and TKI. Natterin N-terminal peptide showed no similarity with already known proteins present in databanks. Primary structure of natterin was obtained by a transcriptomic approach using a representative cDNA library constructed from T. nattereri venom glands. Several expressed sequence tags (ESTs) were obtained and processed by bioinformatics revealing a major group (18%) of related sequences unknown to gene or protein sequence databases. This group included sequences showing the N-terminus of isolated natterin and was named Natterin family. Analysis of this family allowed us to identify five related sequences, which we called natterin 1-4 and P. Natterin 1 and 2 sequences include the N-terminus of the isolated natterin. Furthermore, internal peptides of natterin 1-3 were found in major spots of whole venom submitted to mass spectrometry/2DGE. Similarly to the ESTs, the complete sequences of natterins did not show any significant similarity with already described tissue kallikreins, kininogenases or any proteinase, all being entirely new. These data present a new task for the knowledge of the action of kininogenases and may help in understanding the mechanisms of T. nattereri fish envenoming, which is an important medical problem in North and Northeast of Brazil.
Assuntos
Animais , Batracoidiformes/metabolismo , Calicreínas/isolamento & purificação , Calicreínas/química , Peixes Venenosos/classificação , Venenos de Peixe/isolamento & purificação , Venenos de Peixe/química , Biblioteca Gênica , Brasil , Cromatografia em Gel , Dados de Sequência Molecular , Eletroforese em Gel Bidimensional , Proteínas , Sequência de AminoácidosRESUMO
Endostatin, a carboxy-terminal fragment of collagen XVIII, has been shown to act as an anti-angiogenic agent that specifically inhibits proliferation of endothelial cells and growth of various primary tumors. Here, we describe the expression by Chinese hamster ovary (CHO) cells of murine endostatin and of a tagged-fusion protein, (his)6-met-endostatin. A dicistronic mRNA expression vector was utilized in which endostatin cDNA was inserted upstream of the amplifiable marker gene, dihydrofolate reductase (DHFR). After transfection of the expression vectors, stepwise increments in methotrexate levels in the culture medium were applied, promoting gene amplification and increasing expression levels of the proteins of interest. The expression level of secreted native endostatin was about 78 microg/mL while the one for secreted (his)6-met-endostatin was about 114 microg/mL, for the best expressing clones. Characterization of physico-chemical and immunological activities of the proteins was performed using SDS-PAGE and Western blotting. The biological activities of recombinant endostatins were tested with a cow pulmonary artery endothelial (C-PAE) cell proliferation assay. Both recombinant endostatin and (his)6-met-endostatin inhibited, in a dose-dependent fashion, growth of C-PAE cells stimulated by basic fibroblast growth factor (bFGF).
Assuntos
Inibidores da Angiogênese/metabolismo , Endostatinas/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Inibidores da Angiogênese/genética , Animais , Células CHO , Divisão Celular/fisiologia , Cricetinae , Endostatinas/química , Endostatinas/genética , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Camundongos , Dobramento de Proteína , Proteínas Recombinantes de Fusão/genética , Tetra-Hidrofolato Desidrogenase/genética , TransfecçãoRESUMO
Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide (pI 10.3) from Crotalus durissus terrificus venom composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of the present study was to carry out a biochemical study and a toxic activity assay on native and irradiated crotamine. Crotamine was purified from C.d. terrificus venom by Sephadex G-100 gel filtration followed by ion-exchange chromatography, and irradiated at 2 mg/ml in 0.15 M NaCl with 2.0 kGy gamma radiation emitted by a 60Co source. The native and irradiated toxins were evaluated in terms of structure and toxic activity (LD50). Irradiation did not change the protein concentration, the electrophoretic profile or the primary structure of the protein although differences were shown by spectroscopic techniques. Gamma radiation reduced crotamine toxicity by 48.3 percent, but did not eliminate it
Assuntos
Animais , Camundongos , Venenos de Crotalídeos , Raios gama , Cromatografia Líquida de Alta Pressão , Radioisótopos de Cobalto , Venenos de Crotalídeos , Eletroforese em Gel de Poliacrilamida , Dose Letal MedianaRESUMO
Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide (pI 10.3) from Crotalus durissus terrificus venom composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of the present study was to carry out a biochemical study and a toxic activity assay on native and irradiated crotamine. Crotamine was purified from C.d. terrificus venom by Sephadex G-100 gel filtration followed by ion-exchange chromatography, and irradiated at 2 mg/ml in 0.15 M NaCl with 2.0 kGy gamma radiation emitted by a 60Co source. The native and irradiated toxins were evaluated in terms of structure and toxic activity (LD50). Irradiation did not change the protein concentration, the electrophoretic profile or the primary structure of the protein although differences were shown by spectroscopic techniques. Gamma radiation reduced crotamine toxicity by 48.3%, but did not eliminate it.
Assuntos
Venenos de Crotalídeos/efeitos da radiação , Raios gama , Animais , Cromatografia Líquida de Alta Pressão , Radioisótopos de Cobalto , Venenos de Crotalídeos/isolamento & purificação , Venenos de Crotalídeos/toxicidade , Eletroforese em Gel de Poliacrilamida , Dose Letal Mediana , Masculino , CamundongosRESUMO
Leishmaniasis is an endemic tropical disease in South America, with few therapeutic approaches. Snake venoms are complex protein mixtures with biological actions that could be used as tools for drug development. Here we show that Bothrops moojeni crude venom presented a killing effect in vitro against Leishmania spp. promastigotes, but not with amastigotes, as determined by a viability assay using the mitochondrial oxidative function. Purification of active fractions from crude venom was performed by molecular exclusion and ion exchange chromatography. Anti-Leishmania and l-amino acid oxidase (L-AAO, EC.1.4.3.2.) activities co-eluted in the same fractions. The molecular weight of the active enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa by SDS--PAGE, with a 4.8 isoelectric point. Using substrate subtraction and catalase for scavenging, the action of L-AAO was demonstrated to be hydrogen-peroxide-dependent.
Assuntos
Aminoácido Oxirredutases/metabolismo , Aminoácido Oxirredutases/farmacologia , Antiprotozoários/farmacologia , Bothrops , Venenos de Crotalídeos/farmacologia , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Leishmania/efeitos dos fármacos , Aminoácido Oxirredutases/isolamento & purificação , Animais , Antiprotozoários/isolamento & purificação , Venenos de Crotalídeos/química , Técnicas In Vitro , L-Aminoácido OxidaseRESUMO
Bothrops venoms are complex mixtures of components with a wide range of biological activities. Among these substances, myotoxins have been investigated by several groups. Bothropstoxin-1 (Bthtx-1) is a phospholipase A2-like basic myotoxin from Bothrops jararacussu. The purification of this component involves two chromatographic steps. Although providing a pure material, the association of these two steps is time consuming and a single-step method using high performance chromatography media would be useful. In the present study, we describe a single-step purification method for Bthtx-1. Bothrops jararacussu venom was dissolved in 1 ml buffer. After centrifugation, the supernatant was injected into a Resource-S cation exchange column connected to an FPLC system and eluted with a linear salt gradient. The complete procedure took 20 min, representing a considerable time gain when compared to a previously described method (Homsi-Brandenburgo MI et al. (1988) Toxicon, 26: 615-627). Bthtx-1 purity and identity, assessed by SDS-PAGE and N-terminal sequencing, resulted in a single band with a molecular mass of about 14 kDa and the expected sequence of the first 5 residues, S-L-F-E-L. Although the amount of protein purified after each run is lower than in the previously described method, we believe that this method may be useful for small-scale purifications
Assuntos
Animais , Venenos de Crotalídeos/isolamento & purificação , Fosfolipases A/análise , Bothrops , Cromatografia Líquida de Alta Pressão/métodos , Venenos de Crotalídeos/química , Venenos de Crotalídeos/enzimologia , Fatores de TempoRESUMO
Bothrops venoms are complex mixtures of components with a wide range of biological activities. Among these substances, myotoxins have been investigated by several groups. Bothropstoxin-1 (Bthtx-1) is a phospholipase A2-like basic myotoxin from Bothrops jararacussu. The purification of this component involves two chromatographic steps. Although providing a pure material, the association of these two steps is time consuming and a single-step method using high performance chromatography media would be useful. In the present study, we describe a single-step purification method for Bthtx-1. Bothrops jararacussu venom was dissolved in 1 ml buffer. After centrifugation, the supernatant was injected into a Resource-S cation exchange column connected to an FPLC system and eluted with a linear salt gradient. The complete procedure took 20 min, representing a considerable time gain when compared to a previously described method (Homsi-Brandenburgo MI et al. (1988) Toxicon, 26: 615-627). Bthtx-1 purity and identity, assessed by SDS-PAGE and N-terminal sequencing, resulted in a single band with a molecular mass of about 14 kDa and the expected sequence of the first 5 residues, S-L-F-E-L. Although the amount of protein purified after each run is lower than in the previously described method, we believe that this method may be useful for small-scale purifications.