Amyloidogenic model peptides as catalysts for stereoselective aldol reactions

Autor(es)

Pelin, Juliane N. B. D. ^[1] ; Gerbelli, Barbara B. ^[1] ; Soares, Bruna M. ^[1] ; Aguilar, Andrea M. ^[2] ; Alves, Wendel A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210580 Santo Andre - Brazil

^[2] Univ Fed Sao Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema - Brazil

• Tipo de documento: Artigo Científico
• Fonte: CATALYSIS SCIENCE & TECHNOLOGY; v. 9, n. 16, p. 4304-4313, AUG 21 2019.
• Citações Web of Science: 0

Resumo

In this work, the self-assembly in an aqueous medium of two compounds derived from amyloid-like structures, {[}RF](4) and P{[}RF](4) (where: R = arginine; F = phenylalanine; P = proline), was studied by using spectroscopy, microscopy, and scattering techniques. The peptides presented a similar critical aggregation concentration (cac) considering the same medium conditions (similar to 0.35 mmol L-1 at 25 degrees C). The stability of the systems was analyzed by zeta potential measurements, which showed that under acidic and neutral conditions the colloidal particles remained stable, and for basic solutions, strongly interacting colloids and supramolecular aggregates in solution were observed. CD data confirmed the changes in the conformation of the secondary structures for both compounds by changing the pH of the solution. By SAXS, the curves were fitted using a fractal structure factor, and we observed that the size of the monomers that compose the fractal aggregates of {[}RF](4) is twice as large as that of P{[}RF](4). These compounds showed potential as catalysts in aldol reactions, using cyclohexanone and p-nitrobenzaldehyde. In this case, under optimized reaction conditions, 78% conversion (ee up to 85%) was observed in {[}RF](4) solutions, while P{[}RF](4) had only 51% conversion (ee up to 85%). Our results show, for the first time, a dependence of the morphology on the stereoselective aldol reactions, whereas the folding arrangement of the chiral assemblies in the polypeptide chains plays an essential role in the access of the reactants to the active surface sites. (AU)

• Processo FAPESP: 14/50867-3 - INCT 2014: Instituto Nacional de Ciência e Tecnologia de Bioanalítica
• Beneficiário: Marco Aurelio Zezzi Arruda
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 17/02317-2 - Interfaces em materiais: propriedades eletrônicas, magnéticas, estruturais e de transporte
• Beneficiário: Adalberto Fazzio
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 18/05888-3 - Biossensores baseados em peptídeos anfifílicos para detecção e diagnóstico de doenças
• Beneficiário: Barbara Bianca Gerbelli
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/20446-9 - Estudo da auto-organização de estruturas hierárquicas de peptídeos em solução em presença de nanopartículas metálicas
• Beneficiário: Juliane Nogueira Batista Dias Pelin
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto