Assuntos
Glucosídeos/isolamento & purificação , Fenóis/isolamento & purificação , Plantago/química , Sementes/química , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Glucosídeos/química , Glucosídeos/farmacologia , Estrutura Molecular , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/químicaRESUMO
Antimicrobial peptides (AMPs), named lycocitin 1, 2 and 3, and a peptide with a monoisotopic molecular mass of 3038.70 Da were detected in the venom glands of the wolf spider Lycosa singoriensis. Two of the peptides, lycocitin 1 and 2, are new AMPs whereas lycocitin 3 is highly homologous to lycotoxin II isolated from the venom of spider Lycosa carolinensis. In addition, two other peptides with monoisotopic masses of 2034.20 and 2340.28 Da showing the motif typical for antimicrobial peptides were also identified. These peptides and lycocitin 1, 2 and 3 were de novo sequenced using electron capture dissociation and low-energy collisional tandem mass spectrometry. The amino acid sequence of lycocitin 1 was determined as GKLQAFLAKMKEIAAQTL-NH(2). Lycocitin 2 differs from lycocitin 1 by a replacement of a lysine residue for an arginine residue at the second position. Lycocitin 3 differs from the known lycotoxin II consisting of 27 amino acid residues by a deletion of Gly-26. Both lycocitin 1 and 2 inhibit growth of Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria and fungi (Candida albicans, Pseudomonas aeruginosa) at micromolar concentrations.
Assuntos
Antibacterianos/análise , Glândulas Exócrinas/química , Peptídeos , Venenos de Aranha/química , Sequência de Aminoácidos , Animais , Antibacterianos/química , Dados de Sequência Molecular , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
A fragment of the structural gene of alpha-latrocrustotoxin, a new representative of latrotoxins from black widow spider venom, was cloned. The fragment (1191 bp) was obtained by means of PCR based on the data obtained by sequencing tryptic peptides of the toxin. The fragment codes for a 397-aa sequence. The encoded polypeptide is the C-terminal fragment of the toxin central domain that presumably contains a site responsible for the toxin species specificity. The structural similarity of this fragment to the corresponding fragments of other latrotoxins was studied.
Assuntos
Viúva Negra , DNA Complementar/genética , Venenos de Aranha/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Dados de Sequência MolecularRESUMO
The structural gene of delta-latroinsectotoxin was cloned and its nucleotide sequence was determined. The gene contains an open reading frame of 3642 bp. The deduced amino acid sequence is homologous to the sequences of latrotoxins studied earlier.
Assuntos
Venenos de Aranha/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Viúva Negra , Clonagem Molecular , Dados de Sequência Molecular , Fases de Leitura AbertaRESUMO
The N-terminal amino acid sequence of alpha-latroinsectotoxin from the venom of Latrodectus mactans tredecimguttatus was determined. Then the toxin was digested by trypsin and total or partial amino acid sequences of twenty-six tryptic peptides were established. This resulted in the structural information needed for the construction of probes followed by the cloning of the alpha-latroinsectotoxin structural gene.
Assuntos
Viúva Negra/metabolismo , Venenos de Aranha/genética , Sequência de Aminoácidos , Animais , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Genes , Dados de Sequência Molecular , Mapeamento de Peptídeos , TripsinaRESUMO
The N-terminal amino acid sequence of a neurotoxin from the venom of Latrodectus mactans tredecimguttatus (alpha-latrotoxin) was determined. Latrotoxin was subjected to the tryptic cleavage and total or partial amino acid sequences of 25 peptides were established. In total the tryptic fragments contained 252 amino acid residues. Essential structural information on cloning of the latrotoxin structural gene was obtained.
Assuntos
Viúva Negra , Venenos de Aranha/genética , Sequência de Aminoácidos , Animais , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Genes , Dados de Sequência Molecular , Mapeamento de Peptídeos , TripsinaRESUMO
The 40 kDa argiopinin-binding glycoprotein has been isolated from the solubilised preparations of bovine cerebrum membranes by means of two-step biospecific chromatography on affinity sorbents with immobilized glutamate and argiopinins. This receptor component displays a specific L-[3H]glutamate binding with Kd = 0.18 +/- +/- 0.019 mumole and Bmax = 43 +/- 4.5 nmole/mg. Amino acid analysis reveals it to be a member of integral membrane proteins.
Assuntos
Proteínas de Transporte/metabolismo , Córtex Cerebral/metabolismo , Glicoproteínas de Membrana/metabolismo , Oligopeptídeos/metabolismo , Poliaminas/metabolismo , Aminoácidos/metabolismo , Animais , Proteínas de Transporte/isolamento & purificação , Bovinos , Cromatografia de Afinidade , Eletroforese em Gel de Poliacrilamida , Glutamatos/metabolismo , Ácido Glutâmico , Cinética , Receptores de Glutamato , Receptores de Neurotransmissores/metabolismoAssuntos
Química Encefálica , Proteínas de Transporte/isolamento & purificação , Oligopeptídeos/metabolismo , Poliaminas/metabolismo , Animais , Bovinos , Córtex Cerebral/metabolismo , Cromatografia Líquida , Eletroforese em Gel de Poliacrilamida , Glutamatos/isolamento & purificação , Ácido Glutâmico , Receptores de Glutamato , Receptores de Neurotransmissores/isolamento & purificação , Venenos de AranhaRESUMO
The neurotoxin Os-1 from the venom of the Central Asian scorpion Orthochirus scrobiculosus possesses a high paralytic activity against mice. This neurotoxin was subjected to tryptic, chymotryptic and BrCN cleavages and its total amino acid sequence was established. It was shown that neurotoxin Os-1 consists of 66 amino acid residues an contains four disulfide bonds.