RESUMO
The cDNA coding for a polyunsaturated fatty acid elongase (McELOVL5) was isolated from the brain of the pike eel (Muraenesox cinereus) being based on available sequences in 23 types of fish. Four sequence variants were identified with different amino acid substitutions as compared with two clones of McELOVL5 gene (McELOVL5 11.7 and McELOVL5 12.4). When the two variants of McELOVL5 were expressed in Saccharomyces cerevisiae, the two recombinant yeasts elongated γ-linolenic acid (GLA, 18:3n-6) to di-homo-γ-linolenic acid (DGLA, 20:3n-6) but differed in the rate of GLA conversion to DGLA. Cells transformed with McELOVL5 12.4 also converted arachidonic acid (20:4n-6) and eicosapentaenoic acid (20:5n-3) to docosatetraenoic acid (22:4n-6) and docosapentaenoic acid (22:5n-3), respectively. However McELOVL5 11.7 lost its function for the elongation of C20 fatty acids. The four sequence variants have changed substrate specificities. Three-dimensional models of the McELOVL5 proteins are suggested.
Assuntos
Acetiltransferases/química , Acetiltransferases/metabolismo , Enguias/genética , Acetiltransferases/genética , Sequência de Aminoácidos , Animais , Química Encefálica , Clonagem Molecular , Elongases de Ácidos Graxos , Ácidos Graxos/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , RNA/genética , RNA/isolamento & purificação , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Alinhamento de SequênciaRESUMO
Influenza virus infects host cells through membrane fusion, a process mediated by the low pH-induced conformational change of the viral surface glycoprotein haemagglutinin (HA). We determined the structures and biochemical properties of the HA proteins from A/Korea/01/2009 (KR01), a 2009 pandemic strain, and A/Thailand/CU44/2006 (CU44), a seasonal strain. The crystal structure of KR01 HA revealed a V-shaped head-to-head arrangement, which is not seen in other HA proteins including CU44 HA. We isolated a broadly neutralizing H1-specific monoclonal antibody GC0757. The KR01 HA-Fab0757 complex structure also exhibited a head-to-head arrangement of HA. Both native and Fab complex structures reveal a different spatial orientation of HA1 relative to HA2, indicating that HA is flexible and dynamic at neutral pH. Further, the KR01 HA exhibited significantly lower protein stability and increased susceptibility to proteolytic cleavage compared with other HAs. Our structures provide important insights into the conformational flexibility of HA.
Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Orthomyxoviridae/química , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/isolamento & purificação , Cristalografia por Raios X , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Humanos , Modelos Moleculares , Orthomyxoviridae/imunologia , Conformação Proteica , Estabilidade Proteica , ProteóliseRESUMO
Influenza epidemics arise through the accumulation of viral genetic changes. The emergence of new virus strains coincides with a higher level of influenza-like illness (ILI), which is seen as a peak of a normal season. Monitoring the spread of an epidemic influenza in populations is a difficult and important task. Twitter is a free social networking service whose messages can improve the accuracy of forecasting models by providing early warnings of influenza outbreaks. In this study, we have examined the use of information embedded in the Hangeul Twitter stream to detect rapidly evolving public awareness or concern with respect to influenza transmission and developed regression models that can track levels of actual disease activity and predict influenza epidemics in the real world. Our prediction model using a delay mode provides not only a real-time assessment of the current influenza epidemic activity but also a significant improvement in prediction performance at the initial phase of ILI peak when prediction is of most importance.
Assuntos
Previsões/métodos , Influenza Humana/epidemiologia , Adolescente , Adulto , Feminino , Humanos , Internet/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
A series of 58 3-arylisoquinoline antitumor agents were investigated for defining the pharmacophore model using comparative molecular field analysis (CoMFA) program. The studied compounds related to bioisostere of benzophenanthridine alkaloid were synthesized and evaluated for antitumor cytotoxicity against human lung tumor cell (A 549). In order to perform the systematic molecular modeling study of these compounds, the conformational search was carried out based on the single X-ray crystallographic structure of 7,8-dimethoxy-3-phenylisoquinolin-(2H)-one (2). Interestingly, two types of structures having different dihedral angles between the isoquinoline ring and 3-aryl ring were found in the crystals. Therefore, CoMFA was performed two different, overlapping ways. The alignments of the structures were based on the common isoquinoline ring and 3-aryl ring. The 3-D-quantitative structure-activity relationship study resulted in significant cross-validated, conventional r(2) values equal to 0.715 and 0.927, respectively.