Estudo da atividade inseticida de algumas espécies vegetais.

Foram estudadas 30 espécies vegetais, quanto a atividade inseticida. A partir das diferentes partes desses vegetais foram preparados 240 extratos, utilizando hexano, acetona, etanol 96 e 30 GL, como líquidos extratores. Os testes foram efetuados contra os insetos: Musca domestica, Ceratitis capitata Zabrotes subfasciatus, Spodoptera frugiperda e Anthonomus grandis. Dos vegetais testados, os melhores resultados foram apresentados pelos extratos: hexanico de sementes de Annona crassiflora, hidroalcoolico de raiz de potomorphe umbellata, contra Ceratilis capitata e zabrotes subfasciatus, respectivamente; extratos acetônicos de sementes de Annona cacans e A. squamosa contra Musca domestica; extrato hexanico de sementes Carpotroche brasiliensis contra Ceratilis capitata e extratos etanolicos de frutos e sementes de A. squamosa contra Spodoptera frugiperda. Entre os vegetais que apresentaram atividade, observou-se predominância de espécies da família Annonaceae

Tryptophan-Accelerated Electron Flow Across a Protein−Protein Interface

We report a new metallolabeled blue copper protein, Re126W122Cu^I Pseudomonas aeruginosa azurin, which has three redox sites at well-defined distances in the protein fold: Re^I(CO)_3(4,7-dimethyl-1,10-phenanthroline) covalently bound at H126, a Cu center, and an indole side chain W122 situated between the Re and Cu sites (Re-W122(indole) = 13.1 Å, dmp-W122(indole) = 10.0 Å, Re-Cu = 25.6 Å). Near-UV excitation of the Re chromophore leads to prompt Cu^I oxidation (<50 ns), followed by slow back ET to regenerate Cu^I and ground-state Re^I with biexponential kinetics, 220 ns and 6 μs. From spectroscopic measurements of kinetics and relative ET yields at different concentrations, it is likely that the photoinduced ET reactions occur in protein dimers, (Re126W122CuI)2 and that the forward ET is accelerated by intermolecular electron hopping through the interfacial tryptophan: ^*Re//←W122←Cu^I, where // denotes a protein–protein interface. Solution mass spectrometry confirms a broad oligomer distribution with prevalent monomers and dimers, and the crystal structure of the Cu^(II) form shows two Re126W122Cu^(II) molecules oriented such that redox cofactors Re(dmp) and W122-indole on different protein molecules are located at the interface at much shorter intermolecular distances (Re-W122(indole) = 6.9 Å, dmp-W122(indole) = 3.5 Å, and Re-Cu = 14.0 Å) than within single protein folds. Whereas forward ET is accelerated by hopping through W122, BET is retarded by a space jump at the interface that lacks specific interactions or water molecules. These findings on interfacial electron hopping in (Re126W122Cu^I)^2 shed new light on optimal redox-unit placements required for functional long-range charge separation in protein complexes

Correlation Index-Based Responsible-Enzyme Gene Screening (CIRES), a Novel DNA Microarray-Based Method for Enzyme Gene Involved in Glycan Biosynthesis

BACKGROUND: Glycan biosynthesis occurs though a multi-step process that requires a variety of enzymes ranging from glycosyltransferases to those involved in cytosolic sugar metabolism. In many cases, glycan biosynthesis follows a glycan-specific, linear pathway. As glycosyltransferases are generally regulated at the level of transcription, assessing the overall transcriptional profile for glycan biosynthesis genes seems warranted. However, a systematic approach for assessing the correlation between glycan expression and glycan-related gene expression has not been reported previously. METHODOLOGY: To facilitate genetic analysis of glycan biosynthesis, we sought to correlate the expression of genes involved in cell-surface glycan formation with the expression of the glycans, as detected by glycan-recognizing probes. We performed cross-sample comparisons of gene expression profiles using a newly developed, glycan-focused cDNA microarray. Cell-surface glycan expression profiles were obtained using flow cytometry of cells stained with plant lectins. Pearson's correlation coefficients were calculated for these profiles and were used to identify enzyme genes correlated with glycan biosynthesis. CONCLUSIONS: This method, designated correlation index-based responsible-enzyme gene screening (CIRES), successfully identified genes already known to be involved in the biosynthesis of certain glycans. Our evaluation of CIRES indicates that it is useful for identifying genes involved in the biosynthesis of glycan chains that can be probed with lectins using flow cytometry