Novel aminoquinoline-based solvatochromic fluorescence probe: Interaction with albumin, lysozyme and characterization of amyloid fibrils

Autor(es)

Pastrello, Bruna ^[1] ; dos Santos, Giovanny Carvalho ^[1] ; da Silva-Filho, Luiz Carlos ^[1] ; de Souza, Aguinaldo Robinson ^[1] ; Morgon, Nelson Henrique ^[2] ; Ximenes, Valdecir Farias ^[1]

Afiliação do(s) autor(es)

^[1] UNESP Sao Paulo State Univ, Fac Sci, Dept Chem, BR-17033360 Bauru, SP - Brazil

^[2] Campinas State Univ UNICAMP, Inst Chem, Dept Phys Chem, BR-13083861 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: DYES AND PIGMENTS; v. 173, FEB 2020.
• Citações Web of Science: 1

Resumo

A novel aminoquinoline derivative (AQ) was synthesized and applied as a solvatochromic fluorescent probe to study proteins and their alterations. AQ is not fluorescent in aqueous solution but has its fluorescence quantum yield significantly increased upon binding to albumin. The generation of an induced circular dichroism signal in AQ confirmed the complexation. The Job's plot method revealed an 1:1 stoichiometry for the host-guest complex. The binding constant was determined by AQ fluorescence increase (2.7 x 10(5) mol(-1) L) and by protein intrinsic fluorescence quenching (5.1 x 10(5) mol(-1) L). The displacement of AQ from albumin by warfarin and ibuprofen showed that Sudlow's drug site-I is the preferential binding site. By applying the Bilot-Kawski solvatochromic model to the spectral shifts of fifteen solvents, the microenvironment dielectric constant at albumin site-I was estimated (epsilon = 14.8). In agreement, the average fluorescence lifetime of AQ complexed with albumin (6.11 ns) was close to dichloromethane (6.53 ns) and acetone (6.34 ns), which have dielectric constants of 8.9 and 21.0, respectively. Albumin was thermically treated to formation of amyloid fibril aggregates. AQ was able to differentiate the altered and native protein. Sodium dodecyl sulfate-induced aggregation of lysozyme to amyloid fibril was also efficiently detected by the AQ fluorescence increase. AQ was as efficient as the chromogenic bromocresol purple in the quantitative analysis of albumin. In conclusion, AQ can be considered a new solvatochromic fluorescent probe with several potential applications. (AU)

• Processo FAPESP: 15/00615-0 - Estudos sobre a síntese e caracterização fotoquímica e fotofísica de derivados quinolínicos com estrutura doador-p-aceptor, para utilização como corantes sensibilizadores de dispositivos eletrônicos orgânicos
• Beneficiário: Giovanny Carvalho dos Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 15/22338-9 - Estudo da interação entre fármacos e a albumina do soro humano (HSA) baseado em simulação computacional, DFT e TDDFT, experimentos de dicroísmo circular eletrônico, ECD, e determinação da constante de ligação
• Beneficiário: Aguinaldo Robinson de Souza
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 16/20549-5 - Desenvolvimento e aplicação de sondas fluorescentes e baseadas em dicroísmo circular para estudos de interação de ligantes com proteínas, caracterização de proteínas amiloides e determinação de atividade enzimática
• Beneficiário: Valdecir Farias Ximenes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/14506-7 - Estudo sobre a síntese "one-pot" e aplicação como corantes orgânicos de derivados quinolínicos e antrazolínicos
• Beneficiário: Luiz Carlos da Silva Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50926-0 - INCT 2014: biodiversidade e produtos naturais
• Beneficiário: Vanderlan da Silva Bolzani
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Temático