RESUMO
Naturally occurring antimicrobial peptides take place in the first line of host defense against pathogen as part of the humoral innate immune response. ß-defensins are among the most abundant antimicrobial peptides in mammals, and thought to be solely found in vertebrates until a recent report describing the cloning and sequencing of defensin like peptides in the spiny lobster Panulirus japonicus. In the current study, we cloned and sequenced two genes from the hemocytes of the spiny lobster Panulirus argus encoding for two isoforms of defensin-like peptides, thus confirming the presence of this protein in the Panulirus genus. The 44 amino acids mature peptides showed the conservation of cysteine pattern characterizing the ß-defensins, as well as known amino acids residues critical to exert their antimicrobial activity. They are also amphipathics, hydrophobics, and display an overall positive charge (+1) located at the C-terminus. The tertiary structure obtained by homology modeling indicated that likely conformations of lobster peptides are highly similar to ß-defensins from vertebrates. The phylogenetic study carried out by probabilistic methods confirmed the relation with ancestral ß-defensin from vertebrates. The finding of a putative defensin-like peptide in the expressed sequence tag (EST) of the lobster Homarus americanus with high homology with those of P. argus described in this study, would indicate the presence of this peptides in Palinuridae family. Taking into account all similarities between these peptides with ß-defensins from vertebrates, it is conceivable to further support the finding of a new family of ß-defensins in invertebrate.
Assuntos
Proteínas de Artrópodes/genética , Defensinas/genética , Palinuridae/genética , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/metabolismo , Sequência de Bases , Clonagem Molecular , Simulação por Computador , Defensinas/química , Defensinas/metabolismo , Etiquetas de Sequências Expressas , Hemócitos/metabolismo , Dados de Sequência Molecular , Nephropidae/química , Nephropidae/genética , Palinuridae/metabolismo , Filogenia , Reação em Cadeia da Polimerase , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , beta-Defensinas/química , beta-Defensinas/genética , beta-Defensinas/metabolismoRESUMO
Se estudian las propiedades de un hidrolizado de gelatina como agente aglutinante para la fabricación de tabletas mediante evaluación comparativa con la gelatina de dos variantes con distinto peso molecular. Se usaron como substrato dos fórmulas de ácido ascórbico, y se discriminaron mediante análisis de varianza los efectos significativos del aglutinante sobre diferentes parámetros de los granulados y tabletas. Se realizaron, además, pruebas adicionales utilizando como material de base, carbón vegetal activado y paracetamol. Se propone la inclusión del producto evaluado en la categoría de aglutinante fuerte y se destaca su amplia versatilidad(AU)
