22 documents found, page 1 of 3
25-hydroxycholesterol effect on membrane structure and mechanical properties
Domingues, Marco; Gomes, Bárbara; Hollmann, Axel; Santos, Nuno C.Cholesterol is responsible for the plasticity of plasma membranes and is involved in physiological and pathophysiological responses. Cholesterol homeostasis is regulated by oxysterols, such as 25-hydroxycholesterol. The presence of 25-hydroxycholesterol at the membrane level has been shown to interfere with several viruses' entry into their target cells. We used atomic force microscopy to assess the effect of 2...
Interactions of “de novo” designed peptides with bacterial membranes: implicati...
Maturana, Patricia; Gonçalves, Sónia; Martinez, Melina; Espeche, Juan C.; Santos, Nuno C.; Semorile, Liliana; Maffia, Paulo C.; Hollmann, AxelAntimicrobial peptides are small molecules that display antimicrobial activity against a wide range of pathogens. In a previous work, by using model membranes we studied P6, a peptide that shows no antimicrobial activity, and P6.2, which exhibits antibacterial activity. In the present work we aimed to unravel the mode of action of these peptides by studying their interaction in vivo with Escherichia coli and St...
Antibacterial activity of prenylated benzopyrans from Peperomia obtusifolia (Pi...
Ruiz Mostacero, Nathalie; Castelli, María Victoria; Cutró, Andrea Carla; Hollmann, Axel; Batista, João Marcos; Furlan, Maysa [UNESP]; Valles, JulietaMade available in DSpace on 2019-10-06T17:12:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01; Peperomia obtusifolia is a herbaceous perennial plant native to the Americas reported as a traditional medicine to treat snake bites and as a skin cleanser. The bioassay-guided fractionation of crude extracts from aerial parts of P. obtusifolia against a panel of clinically important fungi and bacteria,...
Synergistic and antibiofilm activity of the antimicrobial peptide P5 against ca...
Martinez, Melina; Gonçalves, Sónia; Felício, Mário Romão; Maturana, Patricia; Santos, Nuno C.; Semorile, Liliana; Hollmann, Axel; Maffía, Paulo C.In the search for new antimicrobial molecules, antimicrobial peptides (AMPs) offer a viable alternative to conventional antibiotics, as they physically disrupt the bacterial membranes, leading to membrane disruption and eventually cell death. In particular, the group of linear α-helical cationic peptides has attracted increasing research and clinical interest. The AMP P5 has been previously designed as a cation...
Effect of 25-hydroxycholesterol in viral membrane fusion : insights on HIV inhi...
Gomes, Bárbara; Abreu, Sónia Gonçalves; Disalvo, Anibal; Hollmann, Axel; Santos, Nuno C.Recently, it was demonstrated that 25-hydroxycholesterol (25HC), an oxidized cholesterol derivative, inhibits human immunodeficiency virus type 1 (HIV) entry into its target cells. However, the mechanisms involved in this action have not yet been established. The aim of this work was to study the effects of 25HC in biomembrane model systems and at the level of HIV fusion peptide (HIV-FP). Integration of differe...
Interaction of S-layer proteins of Lactobacillus kefir with model membranes and...
Hollmann, Axel; Delfederico, Lucrecia; Santos, Nuno C.; Disalvo, E. Anibal; Semorile, LilianaIn previous works, it was shown that S-layer proteins from Lactobacillus kefir were able to recrystallize and stabilize liposomes, this feature reveling a great potential for developing liposomal-based carriers. Despite previous studies on this subject are important milestones, a number of questions remain unanswered. In this context, the feasibility of S-layer proteins as a biomaterial for drug delivery was ev...
Cell surface damage and morphological changes in Oenococcus oeni after freeze-d...
Bravo-Ferrada, Bárbara Mercedes; Abreu, Sónia Gonçalves; Semorile, Liliana; Santos, Nuno C.; Brizuela, Natalia S.; Elizabeth Tymczyszyn, E.The aim of the present study was to evaluate the effects of freeze-drying in the presence of trehalose as a cryoprotectant, followed by incubation in synthetic wine, on surface damage, viability and l-malic acid consumption of the oenological strain Oenococcus oeni UNQOe 73.2. After freeze-drying, no significant differences were observed in the number of viable cells (for both acclimated and non-acclimated cult...
Designing improved active peptides for therapeutic approaches against infectiou...
Gomes, Bárbara; Augusto, Marcelo T.; Felício, Mário Romão; Hollmann, Axel; Franco, Octávio L.; Abreu, Sónia Gonçalves; Santos, Nuno C.Infectious diseases are one of the main causes of human morbidity and mortality. In the last few decades, pathogenic microorganisms' resistance to conventional drugs has been increasing, and it is now pinpointed as a major worldwide health concern. The need to search for new therapeutic options, as well as improved treatment outcomes, has therefore increased significantly, with biologically active peptides repr...
Study of the interactions of bovine serum albumin with a molybdenum(II) carbony...
Jeremias, Hélia F.; Lousa, Diana; Hollmann, Axel; Coelho, Ana C.; Baltazar, Carla S.; Seixas, João D.; Marques, Ana R.; Santos, Nuno C.Therapy with inhaled carbon monoxide (CO) is being tested in human clinical trials, yet the alternative use of prodrugs, CO-Releasing Molecules (CORMs), is conceptually advantageous. These molecules are designed to release carbon monoxide in specific tissues, in response to some locally expressed stimulus, where CO can trigger a cytoprotective response. The design of such prodrugs, mostly metal carbonyl complex...
Lipophilicity is a key factor to increase the antiviral activity of HIV neutral...
Augusto, Marcelo T.; Hollmann, Axel; Troise, Fulvia; Veiga, Ana S.; Pessi, Antonello; Santos, Nuno C.The HIV broadly neutralizing antibody 2F5 targets the transiently exposed epitope in the membraneproximal external region (MPER) of HIV-1 gp41, by a two-step mechanism involving the viral membraneand this viral glycoprotein. It was recently shown that 2F5 conjugation with a cholesterol moiety outsideof the antibody paratope substantially increases its antiviral activity. Additionally, the antiviral activityof D...