Autor(es)

da Cunha, Antonio R. ; Duarte, Evandro L. ; Muniz, Gabriel S. Vignoli ; Coutinho, Kaline ; Lamy, M. Teresa

• Tipo de documento: Artigo Científico
• Fonte: Biophysical Chemistry; v. 309, p. 9-pg., 2024-04-04.

Resumo

Emodin is a natural anthraquinone derivative found in nature, widely known as an herbal medicine. Here, the partition, location, and interaction of emodin with lipid membranes of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) are experimentally investigated with different techniques. Our studies have considered the neutral form of emodin (EMH) and its anionic/deprotonated form (EM-), and their interaction with a more and less packed lipid membrane, DMPC at the gel and fluid phases, respectively. Though DSC results indicate that the two species, EMH and EM-, similarly disrupt the packing of DMPC bilayers, spin labels clearly show that EMH causes a stronger bilayer disruption, both in gel and fluid DMPC. Fluorescence spectroscopy shows that both EMH and EM- have a high affinity for DMPC: the binding of EM- to both gel and fluid DMPC bilayers was found to be quite similar, and similar to that of EMH to gel DMPC, Kp = (1.4 +/- 0.3)x103. However, EMH was found to bind twice more strongly to fluid DMPC bilayers, Kp = (3.2 +/- 0.3)x103. Spin labels and optical absorption spectroscopy indicate that emodin is located close to the lipid bilayer surface, and suggest that EM- is closer to the lipid/water interface than EMH, as expected. The present studies present a relevant contribution to the current understanding of the effect the two species of emodin, EMH and EM-, present on different microregions of an organism, as local pH values can vary significantly, can cause in a neutral lipid membrane, either more or less packed, liked gel and fluid DMPC, respectively, and could be extended to lipid domains of biological membranes. (AU)

• Processo FAPESP: 17/25930-1 - Caracterização de dispersões lipídicas de interesse biológico: estruturas e interações
• Beneficiário: Maria Teresa Moura Lamy
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 21/01593-1 - Múltiplas técnicas físicas na caracterização estrutural de membranas lipídicas de interesse biológico
• Beneficiário: Maria Teresa Moura Lamy
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50983-3 - INCT 2014: fluidos complexos
• Beneficiário: Antonio Martins Figueiredo Neto
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 21/09016-3 - Caracterização estrutural e eletrônica de moléculas biogênicas emitidas pela flora amazônica
• Beneficiário: Kaline Rabelo Coutinho
• Modalidade de apoio: Auxílio à Pesquisa - Regular