RESUMEN
OBJECTIVE: To investigate the oil body protein and function in seeds of mature seagrass, Thalassia hemprichii. RESULTS: Seeds of mature seagrass T. hemprichii when stained with a fluorescent probe BODIPY showed the presence of oil bodies in intracellular cells. Triacylglycerol was the major lipid class in the seeds. Protein extracted from seagrass seeds was subjected to immunological cross-recognition with land plant seed oil body proteins, such as oleosin and caleosin, resulting in no cross-reactivity. An oleosin-like gene was found in seagrass seeds. Next generation sequencing and sequence alignment indicated that the deduced seagrass seed oleosin-like protein has a central hydrophobic domain responsible for their anchoring onto the surface of oil bodies. Phylogenetic analysis showed that the oleosin-like protein was evolutionarily closer to pollen oleosin than to seed oleosins. CONCLUSION: Oil body protein found in seagrass seeds represent a distinct class of land seed oil body proteins.
Asunto(s)
Hydrocharitaceae/embriología , Gotas Lipídicas/metabolismo , Proteínas de Plantas/genética , Semillas/genética , Clonación Molecular , Secuenciación de Nucleótidos de Alto Rendimiento , Hydrocharitaceae/genética , Hydrocharitaceae/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Dominios Proteicos , Semillas/metabolismo , Alineación de Secuencia , Análisis de Secuencia de ADN , Triglicéridos/metabolismoRESUMEN
Sesame (Sesamum indicum L.) seed has been recognized as a nutritional protein source owing to its richness in methionine. Storage proteins have been implicated in allergenic responses to sesame consumption. Two abundant storage proteins, 11S globulin and 2S albumin, constitute 60-70 and 15-25% of total sesame proteins, respectively. Two gene families separately encoding four 11S globulin and three 2S albumin isoforms were identified in a database search of 3328 expressed sequence tag (EST) sequences from maturing sesame seeds. Full-length cDNA sequences derived from these two gene families were completed by PCR using a maturing sesame cDNA library as the template. The amino acid compositions of these deduced storage proteins revealed that the richness in methionine is attributed mainly to two 2S albumin isoforms and partly to one 11S globulin isoform. The presence of four 11S globulin and three 2S albumin isoforms resolved in SDS-PAGE was confirmed by MALDI-MS analyses. The abundance of these isoforms was in accord with the occurrence frequency of their EST sequences in the database. A comprehensive understanding of these storage proteins at the molecular level may also facilitate the identification of allergens in crude sesame products that have caused severe allergic reactions increasingly reported in the past decade.
Asunto(s)
Proteínas de Plantas/genética , Isoformas de Proteínas/genética , Semillas/química , Sesamum/química , Sesamum/genética , Albúminas/química , Albúminas/genética , Albúminas/aislamiento & purificación , Secuencia de Aminoácidos , ADN Complementario/química , ADN de Plantas/química , Biblioteca de Genes , Datos de Secuencia Molecular , Proteínas de Plantas/química , Reacción en Cadena de la Polimerasa , Isoformas de Proteínas/química , Alineación de SecuenciaRESUMEN
A chimeric gene encoding a precursor polypeptide of sesame 2S albumin, a sulfur-rich seed storage protein, was expressed in transgenic rice plants under the control of the glutelin promoter with the aim of improving the nutritive value of rice. Rice grains harvested from the first generation of ten different transformed lines inherited the transgene, and the accumulated sesame 2S albumin was presumably processed correctly as its mature form in sesame seed. This transgene was specifically expressed in maturing rice seeds with its encoded sesame 2S albumin exclusively accumulated in the seeds. The crude protein content in rice grains from five putative homozygous lines was increased by 0.64-3.54%, and the methionine and cysteine contents of these transgenic rice grains were respectively elevated by 29-76% and 31-75% compared with those of wild-type rice grains.
Asunto(s)
Albúminas/metabolismo , Cisteína/metabolismo , Metionina/metabolismo , Oryza/metabolismo , Plantas Modificadas Genéticamente/metabolismo , Semillas/metabolismo , Sesamum/genética , Albúminas/biosíntesis , Albúminas/química , Albúminas/genética , Aminoácidos/química , Northern Blotting , Western Blotting , Oryza/genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente/genética , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Semillas/genética , Sesamum/metabolismo , Distribución TisularRESUMEN
An acidic pectin methylesterase (PME) is responsible for the gelation of water extract from jelly fig (Ficus awkeotasang) achenes. A new, fast and efficient, method has been developed to purify this acidic PME. The method includes preparing jelly curd by traditional hand washing, extracting proteins from the curd, and separating PME by anion-exchanger. The purified PME exists as a monomer of 38 kDa determined by gel filtration, and exerts enzymatic activity over a broad pH range, particularly in acidic environments where most known PME enzymes from various species are inactivated. Chemical staining and enzymatic cleavage suggest that the jelly fig PME is an N-linked glycoprotein. Fluorophore-assisted carbohydrate electrophoresis reveals that the polysaccharide of this glycoprotein putatively consists of 22 hexoses including 16 mannose, 4 N-acetylglucosamine, and 2 galactose residues.