RESUMO
A novel lipid-transporting protein (Ns-LTP1) has been isolated from seeds of the garden fennel flower Nigella sativa. The molecular mass, N-terminal amino acid sequence, and amino acid composition of the protein have been determined. Ns-LTP1 has a molecular mass of 9602 Da and contains eight cysteine residues which form four disulfide bridges. The protein is capable of suppressing the development of some phytopathogenic fungi and oomycetes.
Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Proteínas de Transporte/química , Nigella sativa/química , Proteínas de Plantas/química , Sementes/química , Sequência de Aminoácidos , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/farmacologia , Ascomicetos/efeitos dos fármacos , Proteínas de Transporte/isolamento & purificação , Proteínas de Transporte/farmacologia , Fungos Mitospóricos/efeitos dos fármacos , Dados de Sequência Molecular , Oomicetos/efeitos dos fármacos , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologiaRESUMO
A novel lipid transfer protein called Ec-LTP was isolated from resting caryopsis of weed barnyard grass Echinochloa crusgalli (L.) Beauv.; its molecular weight, amino acid content and N-terminal amino acid sequence were determined. Ec-LTP was a 9150 Da protein, containing eight cysteine residues, which formed four disulfide bonds. The isolated protein could significantly inhibit the development of pathogenic fungi Phytophthora infestans and Helminthosporium sativum, causing the late blight of potato and tomato and the root rot of herbs, respectively.
Assuntos
Proteínas de Transporte/química , Proteínas de Transporte/isolamento & purificação , Echinochloa/química , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Sequência de Aminoácidos , Proteínas de Transporte/genética , Echinochloa/genética , Echinochloa/microbiologia , Helminthosporium , Phytophthora infestans , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Análise de Sequência de ProteínaRESUMO
By means of covalent chromatography on thiopropyl-sepharose 6B the N-terminal, as well as other tryptic cysteine-containing peptides of the bovine tryptophanyl-tRNA-synthetase (EC 6.1.1.2) were purified and characterized, their structures being determined by a combination of plasma desorption mass spectrometry and peptide sequencing. In total, six different peptides containing seven cysteine residues were analysed. The N-terminal amino acid (presumably, alanine) was shown to be acetylated in the nature enzyme amino acid sequences of some cysteine-containing peptides proved to differ from those deduced from the cDNA structure, thus indicating the presence of the enzyme's isoforms. The purification does not affect the peptides' sulfhydryl groups. The number of cysteine residues in the peptides could be determined with a high accuracy by measuring their masses before and after alkylation with 4-vinylpyridine.