title: Catalytic DNA-based fluorescence polarization chiral sensing platform for L-histidine detection at trace level.
abstract: This paper reports a novel fluorescence polarization (FP) chiral sensor approach based on a catalytic DNA. This platform involves an enzyme module (E), which was able to trigger the L-histidine-dependent cleavage of an RNA phosphoester bond of a substrate domain (S), whereas it did not accept the D-enantiomer as cofactor. Two assay formats were proposed, based on bi- and unimolecular strategies. The bimolecular design was related to the use of separate E and fluorescently labelled S* sequences. The two oligonucleotide strands were pre-assembled via complementary regions at their extremities. As the result of the large molecular volume of the formed assembly, the S* probe displayed a high fluorescence anisotropy signal. Upon addition of the L-histidine, the DNAzyme cleaved the phosphoester bond of the S* component, leading to the loss of stem stability and the release of single-stranded products of lower size. This was accompanied by a significant decrease in the fluorescence anisotropy response. As a simpler alternative, the unimolecular design, where E and S sequences are linked together through a loop to form a single fluorescent probe E-S*, was also investigated. It was found that the unimolecular approach provided an improved FP response relative to the bimolecular one. Under optimized operating conditions, such a chiral sensing platform allowed the detection of as low as 0.05% of the L-histidine enantiomer in a non-racemic mixture.
authors.affiliation: Département de Pharmacochimie Moléculaire UMR 5063 CNRS, ICMG FR 2607, Université de Grenoble, Campus universitaire, Saint-Martin d'Hères, 38240, France.
authors.forename: Nathalia Braga
authors.initials: NB
authors.lastname: Amaral
authors.forename: Simon
authors.initials: S
authors.lastname: Zuliani
authors.forename: Valérie
authors.initials: V
authors.lastname: Guieu
authors.forename: Corinne
authors.initials: C
authors.lastname: Ravelet
authors.forename: Sandrine
authors.initials: S
authors.lastname: Perrier
authors.forename: Eric
authors.initials: E
authors.lastname: Peyrin
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D021881:DNA, Catalytic / Q000737:chemistry*; D005454:Fluorescence Polarization; D006639:Histidine / Q000737:chemistry*; D007536:Isomerism; D009841:Oligonucleotides / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D021881:DNA, Catalytic; D009841:Oligonucleotides; D006639:Histidine