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PAZIN,WALLANCE M.; SANTOS,SUIKINAI N. DOS; QUEIROZ,SONIA C.N.; BAGATOLLI,LUIS A.; SOARES,ADEMILSON E.E.; MELO,ITAMAR S. DE; ITO,AMANDO S.. |
Abstract: We have established how natural compounds from green propolis collected by the species Apis mellifera act against the growth of Pythium aphanidermatum. On the basis of mass spectrometry (Q-ToF MS), we determined that Artepillin C, the major constituent of green propolis, underlies the effect and displays activity against P. aphanidermatum at a minimal inhibitory concentration of 750 µg.mL-1. Biophysical studies based on model membranes showed that this inhibitory effect may be linked with a membrane-related phenomenon: Artepillin C increases the permeability of membranes with relatively high fluidity in their lateral structure, a feature that is in line with the lipid composition reported for the cytoplasmic membrane of P. aphanidermatum.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Green propolis; Artepillin C; Fungicide; Pythium aphanidermatum; Model membranes. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000300617 |
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Pazin,W.M.; Vilanova,N.; Voets,I.K.; Soares,A.E.E.; Ito,A.S.. |
It has been hypothesized that the therapeutic effects of artepillin C, a natural compound derived from Brazilian green propolis, are likely related to its partition in the lipid bilayer component of biological membranes. To test this hypothesis, we investigated the effects of the major compound of green propolis, artepillin C, on model membranes (small and giant unilamelar vesicles) composed of ternary lipid mixtures containing cholesterol, which display liquid-ordered (lo) and liquid-disordered (ld) phase coexistence. Specifically, we explored potential changes in relevant membrane parameters upon addition of artepillin C presenting both neutral and deprotonated states by means of small angle X-ray scattering (SAXS), differential scanning calorimetry... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artepillin C; Green propolis; Model membranes; Giant unilamellar vesicles; SAXS; DSC. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2019000300610 |
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Goñi,F.M.; Ostolaza,H.. |
Alpha-Hemolysin is synthesized as a 1024-amino acid polypeptide, then intracellularly activated by specific fatty acylation. A second activation step takes place in the extracellular medium through binding of Ca2+ ions. Even in the absence of fatty acids and Ca2+ HlyA is an amphipathic protein, with a tendency to self-aggregation. However, Ca2+-binding appears to expose hydrophobic patches on the protein surface, facilitating both self-aggregation and irreversible insertion into membranes. The protein may somehow bind membranes in the absence of divalent cations, but only when Ca2+ (or Sr2+, or Ba2+) is bound to the toxin in aqueous suspensions, i.e., prior to its interaction with bilayers, can <FONT FACE="Symbol">a</FONT>-hemolysin bind... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Alpha-hemolysin; Bacterial toxins; RTX toxins; Lipid-protein interactions; Calcium-binding proteins; Model membranes. |
Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000800002 |
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