34 research outputs found
Probing Nucleic Acid Structure with Nickel‐ and Cobalt‐Based Reagents
The use of nickel and cobalt reagents is presented for characterizing the solvent exposure of guanine residues in DNA and RNA. These reagents promote guanine oxidation in the presence of a peracid such as monopersulfate, and the extent of reaction indicates the steric and electronic environment surrounding the N7 and aromatic face of this residue. Since oxidation does not itself perturb target structure or induce strand scission, it is coupled with fragmentation by treatment with piperidine (for smaller polynucleotides) or termination of primer extension (for larger polynucleotides).Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143767/1/cpnc0604.pd
The Pediatric Cell Atlas:Defining the Growth Phase of Human Development at Single-Cell Resolution
Single-cell gene expression analyses of mammalian tissues have uncovered profound stage-specific molecular regulatory phenomena that have changed the understanding of unique cell types and signaling pathways critical for lineage determination, morphogenesis, and growth. We discuss here the case for a Pediatric Cell Atlas as part of the Human Cell Atlas consortium to provide single-cell profiles and spatial characterization of gene expression across human tissues and organs. Such data will complement adult and developmentally focused HCA projects to provide a rich cytogenomic framework for understanding not only pediatric health and disease but also environmental and genetic impacts across the human lifespan
Excess Electron Transfer from an Internally Conjugated Aromatic Amine to 5-Bromo-2‘-deoxyuridine in DNA
Inducible Alkylation of DNA by a Quinone Methide–Peptide Nucleic Acid Conjugate
The reversibility of alkylation by a quinone methide
intermediate (QM) avoids the irreversible consumption that plagues
most reagents based on covalent chemistry and allows for site specific
reaction that is controlled by the thermodynamics rather than kinetics
of target association. This characteristic was originally examined
with an oligonucleotide QM conjugate, but broad application depends
on alternative derivatives that are compatible with a cellular environment.
Now, a peptide nucleic acid (PNA) derivative has been constructed
and shown to exhibit an equivalent ability to delivery the reactive
QM in a controlled manner. This new conjugate demonstrates high selectivity
for a complementary sequence of DNA even when challenged with an alternative
sequence containing a single T/T mismatch. Alternatively, alkylation of noncomplementary
sequences is only possible when a template strand is present to colocalize
the conjugate and its target. For efficient alkylation in this example,
a single-stranded region of the target is required adjacent to the
QM conjugate. Most importantly, the intrastrand self-adducts formed
between the PNA and its attached QM remained active and reversible
over more than 8 days in aqueous solution prior to reaction with a
chosen target added subsequently
Single Amino Acid Switch between a Flavin-Dependent Dehalogenase and Nitroreductase
A single
mutation within a flavoprotein is capable of switching
the catalytic activity of a dehalogenase into a nitroreductase.
This change in function correlates with a destabilization of the one-electron-reduced
flavin semiquinone that is differentially expressed in the nitro-FMN
reductase superfamily during redox cycling. The diversity of
function within such a superfamily therefore has the potential
to arise from rapid evolution, and its members should provide a convenient
basis for developing new catalysts with an altered specificity of
choice