Mesquita, Raquel B. R.

Nacapricha, Duangjai

Rangel, António O. S. S.

Thepchuay, Yanisa

English

Repositório Institucional da Universidade Católica Portuguesa

ORAL333QUÍMICA E SAÚDEQS10New fluorophores for protein aggregates detectionR. Nunes da Silva1,2,*, S. I. Vieira2, J. Rocha3, A. M. S. Silva1, S. Guieu1,31QOPNA, Department of Chemistry, University of Aveiro, Aveiro, Portugal2IBiMED, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal3CICECO Aveiro-Institute of Materials, Department of Chemistry, University of Aveiro, Aveiro, Portugal*rsons@ua.ptLuminogenic materials with aggregation-induced emission (AIE) properties have attracted much interest recently [1]. These materials were first discovered in 2001 when a series of silole derivatives were described as non-emissive in dilute solutions but highly luminescent when aggregated in concentrated solutions or casted into solid films [2].Cells express several distinct proteins to convey a diversity of functions. However, under several stress conditions protein misfolding can occur. Misfolded proteins can acquire different forms such as soluble oligomers, amyloid fibrils and amorphous aggregates [3]. Protein aggregation is well documented and is related with aging and age-related diseases, such as neurodegenerative (Alzheimer, Huntington, Parkinson or prion disease), cancer and cardiovascular (atherosclerosis, heart failure and ischemic heart disease) [3]. Fluorescence-based techniques have been a reliable tool on the study of such protein aggregates, especially fluorophores with AIE properties [4].Herein we report our recent work on the synthesis and characterization of new fluorophores, as well as the study of their AIE properties. Their application as protein aggregates fluorosensors will also be addressed. Fig.1. Confocal microscopy imaging of HeLa cells incubated with a inhibitor of the proteasome 5uM MG132 and a. new AIE fluorogen developed by us, b. commercial protein aggregates sensor and c. merged (AIE fluorogen + commercial protein aggregates sensor).ACKNOWLEDGMENTS: This work was supported by University of Aveiro, FCT/MEC, Centro 2020 and Portugal2020, the COMPETE program, and the European Union (FEDER program) via the financial support to the QOPNA research project (FCT UID/QUI/00062/2013), to the IBiMed Research Unit (UID/BIM/04501/2013), to the Portuguese NMR Network, and to the PAGE project “Agregação proteica ao longo da vida” (CENTRO-01-0145-FRDER-000003), including R. Nunes da Silva Post-Doctoral grant (BPD/UI98/6327/2018).REFERÊNCIAS:[1] Y. Hong, J.W.Y. Lam, B.Z. Tang, Chem. Soc. Rev., 40 (2011) 5361; P. Vaz, J. Rocha, A.M.S. Silva, S. Guieu, New J. Chem., 40 (2016) 3; S. Guieu, J. Rocha. A.M.S. Silva, Tetrahedron, 69 (2013) 9329.[2] J. Luo, Z. Xie, J. W. Y. Lam, L. Cheng, H. Chen, C. Qiu, H. S. Kwok, X. Zhan, Y. Liu, D. Zhu and B. Z. Tang, Chem. Commun., 0 (2001) 1740.[3] M. Gouveia, K. Xia, W. Colón, S. I. Vieira, F. Ribeiro, Ageing Res. Ver., 40 (2017) 1; A. G. Kreutzer, J. S. Nowick, Acc. Chem. Res., 51 (2018) 706; M. Arrasate, S. Finkbeiner, Exp Neurol., 238 (2012) 1.[4] C. L, Teoh, D. Su, S. Sahu, S. Yun, E. Drummond, F. Prelli, S. Lim, S. Cho, S. Ham, T. Wisniewski, Y. Chang, J. Am. Chem. Soc., 137 (2015) 13503.cSequential flow injection analysis with potentiometric detection for the determination of ammonium and urea in human salivaYanisa Thepchuay1, Raquel B. R. Mesquita2*, Duangjai Nacapricha1,António O. S. S. Rangel21Faculty of Science, Mahidol University, Rama 6 Road, Thungpayathai, Rachathewi, Bangkok, Thailand 104002Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital 172, 4200-374 Porto, Portugal - *rmesquita@porto.ucp.ptIn this work, a sequential injection (SI) system for the simultaneous determination of ammonium and urea is described. An ammonia ion selective electrode (ISE) was used for potentiometric detection of ammonium. The determination of urea was based on enzymatic hydrolysis using urease to convert urea to ammonium. The urease enzyme was immobilized and packed in a mini-column (E) connected to the selection valve, as shown in Fig.1. After conversion, the stream of the ammonium plug merged with a sodium hydroxide solution to form molecular ammonia and to act as ionic strength adjuster (ISA). The produced ammonia was propelled to the ammonia ISE enabling to determine urea concentration. For ammonium determination, standard solutions were aspirated and propelled to the confluence point to merge with ISA hydroxide solution before reaching the ammonia ISE. This SI method could be useful for fast and sensitive detection to quantify salivary ammonium and urea in patients with some oral or chronic kidney disease.Fig. 1 SI manifold for the determination of urea in human saliva. P1, syringe pump; P2, peristaltic pump; HC1 and HC2, holding coil; E, urease enzymatic reactor; Carrier, deionized water; ISA, 0.2 M NaOH; PB, phosphate buffer (pH 7); S, standard solution or sample; ISE, ammonia ion selective electrode; RE, reference electrode; mV, potentiometer; W, waste.ACKNOWLEDGEMENTS:R.B.R. Mesquita thanks FCT- Fundação para a Ciência e Tecnologia for the grant SFRH/BDP/112032/2015. This work was supported by Nationals Funds from FCT through project UID/Multi/50016/2013

Sequential flow injection analysis with potentiometric detection for the determination of ammonium and urea in human saliva

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Sequential flow injection analysis with potentiometric detection for the determination of ammonium and urea in human saliva

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