Publicação
Fluorimetric sensing of metal cations by di- and tripeptides bearing an unnatural amino acid with chelating ability
| Resumo: | The interest in peptide design with functional properties is a current thrust in research and their molecular design can thus be achieved using non coded amino acids of synthetic origin, which can be effective building blocks as the incorporation of functional unnatural amino acids into peptides may result in the appearance of the inherent functions.[1] These novel amino acids can result from synthetic manipulation at the side chain of coded amino acids, that generate altered physicochemical or photophysical properties. Amino acids, and hence peptides, also display ability to complex metal ions through nitrogen, oxygen and sulfur donor atoms at the mainand side chain, thus the design of peptides that coordinate metals, by incorporation of modified amino acids, has potential for applications as varied as the study on protein-protein interactions mediated by metals, protein binding to nanoparticles and metal surfaces, and the development of selective chemosensors for metals for use in vivoand in vitro.[2] Unnatural amino acids bearing fluorescent heterocyclic moieties have beendescribed as fluorescent and/or colorimetric chemosensors for anions and metal cations and biomarkers.[3] In medicinal chemistry, fluorescent sensors are preferred because they are well suited to meet the need for in vivo probes, such as mapping the spatial and temporal distribution of the biological analytes, and they have other advantages including extremely high sensitivity, relatively low cost and easy availability, as well as multiple modes of detection, such as fluorescence quenching, enhancement and lifetime.[4] Recently, our research group has been involved in the development and application of benz-X-azole-containing amino acids with application as fluorescent probes and metal ion chemosensors, namely benzoxazolyl-alanines, thiadiazolyl-, benzothiazolyl- and benzimidazolyl-asparagines.[5] In the present communication, we report the synthesis and photophysical characterization of three peptides (two tripeptides and one dipeptide) bearing a highly emissive unnatural amino acid withchelating ability. Their potential application as fluorimetric chemosensors for biologically important alkaline, alkaline-earth and transition metallic cations was valuatedby spectrofluorimetric titrations. The study revealed that the chelating ability of the free unnatural amino acid was retained after incorporation into the peptide and the highest sensitivity of detection was achieved for Pd2+ e Hg2+. |
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| Autores principais: | Ribeiro, Gonçalo M. A. |
| Outros Autores: | Raposo, M. Manuela M.; Costa, Susana P. G. |
| Ano: | 2012 |
| País: | Portugal |
| Tipo de documento: | outro |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | The interest in peptide design with functional properties is a current thrust in research and their molecular design can thus be achieved using non coded amino acids of synthetic origin, which can be effective building blocks as the incorporation of functional unnatural amino acids into peptides may result in the appearance of the inherent functions.[1] These novel amino acids can result from synthetic manipulation at the side chain of coded amino acids, that generate altered physicochemical or photophysical properties. Amino acids, and hence peptides, also display ability to complex metal ions through nitrogen, oxygen and sulfur donor atoms at the mainand side chain, thus the design of peptides that coordinate metals, by incorporation of modified amino acids, has potential for applications as varied as the study on protein-protein interactions mediated by metals, protein binding to nanoparticles and metal surfaces, and the development of selective chemosensors for metals for use in vivoand in vitro.[2] Unnatural amino acids bearing fluorescent heterocyclic moieties have beendescribed as fluorescent and/or colorimetric chemosensors for anions and metal cations and biomarkers.[3] In medicinal chemistry, fluorescent sensors are preferred because they are well suited to meet the need for in vivo probes, such as mapping the spatial and temporal distribution of the biological analytes, and they have other advantages including extremely high sensitivity, relatively low cost and easy availability, as well as multiple modes of detection, such as fluorescence quenching, enhancement and lifetime.[4] Recently, our research group has been involved in the development and application of benz-X-azole-containing amino acids with application as fluorescent probes and metal ion chemosensors, namely benzoxazolyl-alanines, thiadiazolyl-, benzothiazolyl- and benzimidazolyl-asparagines.[5] In the present communication, we report the synthesis and photophysical characterization of three peptides (two tripeptides and one dipeptide) bearing a highly emissive unnatural amino acid withchelating ability. Their potential application as fluorimetric chemosensors for biologically important alkaline, alkaline-earth and transition metallic cations was valuatedby spectrofluorimetric titrations. The study revealed that the chelating ability of the free unnatural amino acid was retained after incorporation into the peptide and the highest sensitivity of detection was achieved for Pd2+ e Hg2+. |
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