Hopanoid Hopene Locates in the Interior of Membranes and Affects Their Properties

Autor(es)

Alvares, Dayane S. ^{[1, 2, 3]} ; Crosio, Matias ^{[2, 3]} ; Wilke, Natalia ^{[2, 3]}

Afiliação do(s) autor(es)

^[1] UNESP Sao Paulo State Univ, Dept Phys, IBILCE, BR-15054000 Sao Jose Do Rio Preto, SP - Brazil

^[2] Univ Nacl Cordoba, Fac Ciencias Quim, Dept Quim Biol Ranwel Caputto, CONICET, X5000HUA, Cordoba - Argentina

^[3] Univ Nacl Cordoba, Ctr Invest Quim Biol Cordoba CIQUIBIC, CONICET, X5000HUA, Cordoba - Argentina

• Tipo de documento: Artigo Científico
• Fonte: Langmuir; v. 37, n. 40, p. 11900-11908, OCT 12 2021.
• Citações Web of Science: 0

Resumo

Hopanoids are proposed as sterol surrogates in some bacteria, and it has been proved that some hopanoids are able to induce a liquid-order phase state in lipid membranes. The members of this group of molecules have diverse structures, and not all of them have been studied in detail yet. Here, we study membranes with the hopanoid hopene (hop-22 (29)-ene or diploptene), which is the product of the cycling of squalene by squalene-hopene cyclase, and thus is present in the first step of hopanoid biosynthesis. Hopene is particularly interesting because it lacks a polar head group, which opens the question of how does this molecule accommodate in a lipid membrane, and what are the effects promoted by its presence. In order to get an insight into this, we prepared monolayers and bilayers of a phospholipid with hopene and studied their properties in comparison with pure phospholipid membranes, and with the sterol cholesterol or the hopanoid diplopterol. Film stiffness, shear viscosity, and bending dynamics were very affected by the presence of hopene, while zeta-potential, generalized polarization of Laurdan, and conductivity were affected moderately by this molecule. The results suggest that at very low percentages, hopene locates parallel to the phospholipid molecules, while the excess of the hopene molecules stays between leaflets, as previously proposed using molecular dynamics simulations. (AU)

• Processo FAPESP: 18/14215-2 - Regulação da atividade de peptídeos antimicrobianos pelas propriedades mecânicas da membrana alvo
• Beneficiário: Dayane dos Santos Alvares
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado