Locked nucleic acids (LNA) show remarkable affinity and specificity against native DNA targets. Effects of LNA modifications on mismatch discrimination were studied as a function of sequence context and identity of the mismatch using ultraviolet (UV) melting experiments. A triplet of LNA residues centered on the mismatch was generally found to have the largest discriminatory power. An exception was observed for G-T mismatches, where discrimination decreased when the guanine nucleotide at the mismatch site or even the flanking nucleotides were modified. Fluorescence experiments using 2-aminopurine suggest that LNA modifications enhance base stacking of perfectly matched base pairs and decrease stabilizing stacking interactions of mismatched base pairs. LNAs do not change the amount of counterions (Na+) that are released when duplexes denature. New guidelines are suggested for design of LNA probes, which significantly improve mismatch discrimination in comparison with unmodified DNA probes.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1456327 | PMC |
http://dx.doi.org/10.1093/nar/gkl175 | DOI Listing |
EBioMedicine
January 2025
Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, New Cornerstone Science Foundation, Beijing, 100084, China. Electronic address:
Background: The widespread and evolution of RNA viruses, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlights the importance of fast identification of virus subtypes, particularly in non-laboratory settings. Rapid and inexpensive at-home testing of viral nucleic acids with single-base resolution remains a challenge.
Methods: Topologically constrained DNA ring is engineered as substrates for the trans-cleavage of Cas13a to yield an accelerated post isothermal amplification.
J Neurol
January 2025
Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clínic de Barcelona, Fundació de Recerca Clínic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Villaroel 170, 08036, Barcelona, Spain.
Plasma tau phosphorylated at threonine 181 (p-tau181) and 217 (p-tau217) have demonstrated high accuracy for Alzheimer's disease (AD) diagnosis, defined by CSF/PET amyloid beta (Aβ) positivity, but most studies have been performed in research cohorts, limiting their generalizability. We studied plasma p-tau217 and p-tau181 for CSF Aβ status discrimination in a cohort of consecutive patients attending an academic memory clinic in Spain (July 2019-June 2024). All patients had CSF AD biomarkers performed as part of their routine clinical assessment.
View Article and Find Full Text PDFDiscov Immunol
December 2024
Laboratory of Functional Genomics and Medicine, Division of Biological Science, Nara Institute of Science and Technology (NAIST), Ikoma-shi, Nara, Japan.
Introduction: Programmed death-1 (PD-1) is a negative regulator of immune responses. Upon deletion of PD-1 in mice, symptoms of autoimmunity developed only after they got old. In a model experiment in cancer immunotherapy, PD-1 was shown to prevent cytotoxic T lymphocytes from attacking cancer cells that expressed neoantigens derived from genome mutations.
View Article and Find Full Text PDFBrain Lang
February 2025
Univ. Lille, CNRS, UMR 9193 - SCALab - Sciences Cognitives et Sciences Affectives, F-59000 Lille, France; Univ. Lille, Inria, CNRS, Centrale Lille, UMR 9189 - CRIStAL, F-59000, Lille, France. Electronic address:
Although previous research has shown that speakers adapt on the words they use, it remains unclear whether speakers adapt their phonological representations, leading them to perceive new phonemic contrasts following a social interaction. This event-related potential (ERP) study investigates whether the neuronal responses to the perception of the /e/-/ε/ vowel merger in Northern French speakers show evidence for discriminating /e/ and /ε/ phonemes after interacting with a speaker who produced this contrast. Northern French participants engaged in an interactive map task and we measured their ERP responses elicited after the presentation of a last syllable which was either phonemically identical to or different from preceding syllables.
View Article and Find Full Text PDFInt J Pediatr Otorhinolaryngol
January 2025
Level IV, Department of Health and Human Communication, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil. Electronic address:
Objective: To describe and compare the latencies and amplitudes of Mismatch Negativity between children with and without Developmental Dyslexia.
Methods: Cross-sectional and comparative study, consisting of a study group of 52 children with Developmental Dyslexia and a control group of 52 children with typical development, matched by age and sex, aged between 9 years and 11 years and 11 months of both sexes. All participants underwent Otoscopy, Acoustic Immittance Measurements, Pure Tone Audiometry, Speech Audiometry, Brainstem Auditory Evoked Potential and Mismatch Negativity.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!