Autor(es):
Morgon, Nelson Henrique, 1964-
Data: 2020
Identificador Persistente: https://hdl.handle.net/20.500.12733/1670904
Origem: Oasisbr
Assunto(s): Corantes fluorescentes; Albumina; Fluorescent dyes; Albumin; Solvatochromic fluorescent probe; Aminoquinoline derivative; One-pot synthesis; Lysozyme; Amyloid fibril aggregates; Artigo original; Corantes fluorescentes; Corantes fluorescentes; Albumina; Albumina; Fluorescent dyes; Fluorescent dyes; Albumin; Albumin; Solvatochromic fluorescent probe; Solvatochromic fluorescent probe; Aminoquinoline derivative; Aminoquinoline derivative; One-pot synthesis; One-pot synthesis; Lysozyme; Lysozyme; Amyloid fibril aggregates; Amyloid fibril aggregates; Artigo original; Artigo original
Descrição
Agradecimentos: The authors gratefully acknowledge financial support from Coordination for the Improvement of Higher Education Personnel; National Council for Scientific and Technological Development (CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico, grants #302793/2016-0, #305541/2017-0 and #302769/2018-8), National Institute of Science and Technology - INCT BioNat, grant #465637/2014-0, and the State of Sao Paulo Research Foundation (FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo, grants# 2014/50926-0, #2015/22338-9, #2016/20549-5, #2015/00615-0 and #2018/14506-7)
Abstract: 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 × 105 mol-1 L) and by protein intrinsic fluorescence quenching (5.1 × 105 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 (e = 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
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP
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