Yehl, K.; Joshi, J.P.; Greene, B.L.; Dyer, R. B.; Nahta, R.; Salaita, K. Catalytic Deoxyribozyme-Modified Nanoparticles for RNAi-Independent Gene Regulation, ACS Nano, 2012, 6(10), 9150–9157.
1) 10-23 DNAzyme has a 15 nt catalytic core
2) Has been used as a therapeutic in animal models to block translation of tumorigenic genes
3) Gene regulation with DNAzymes is attractive due to …
a. Low cost of synthesis
b. High selectivity
c. Significant catalytic efficiency
d. Catalytically inhibit translation in an RNAi independent manner
e. Need to solve problems of cellular delivery and intracellular stability
4) What is a nanozyme? It is …
a. Self-assembled multivalent catalytic particle
b. Functions as a single entity
c. Displays enhanced substrate binding and stability
d. Can display higher activity than the individual catalytic subunits
5) DNA-gold nanoparticle conjugates are highly stable
6) They are successful DNA regulators due to having ….
a. Enhanced binding affinities
b. Resistance to nuclease degradation
c. High cellular uptake
d. Diminished cellular toxicity (all compared to free oligonucleotides)
7) The oligonucleotide density of the purified DzT10NPs was 160 10 oligos/particle based on a fluorescence DNA quantification kit (Invitrogen).
Stabley, D.; Schumacher, C.; Marshall, S.; Salaita, K. Visualizing Mechanical Tension Across Membrane Receptors with a Fluorescent Sensor, Nature Methods, 2012, 9, 64-67.
1) Which receptor / ligand pair is this and what cells are being used?
a. ANS: epidermal growth factor receptor (EGFR) and epidermal growth factor (EGF), PDB_ 2KV4.
b. HCC1143 cells – immortalized human breast cancer cells – cultured in RPMI1640 medium (Mediatech)
2) Interplay between physical inputs and chemical reaction cascades is important in the following processes…
a. Epithelial cell adhesion
b. Migration to stem cell differentiation
c. Immune response
3) Most are transduced through membrane receptors that mount a signaling cascade depending on the mechanical properties of their specific cognate ligands.
4) The method described here is a molecular-tension sensor to spatially and temporally map forces exerted by cell-surface receptors.
5) PEG linker was chosen because ….
a. Well-characterized and reversible force-extension curves
c. Minimal nonspecific interactions with other biomolecules
6) The force that the receptor is exerting is more or less being measured in association with Hooke’s Law and spring constants (I'm assuming).
7) Fluorescence returned to background levels (indicating that fluorophore-labeled EGF remains bount ot the sensor surface) may indicate ….
a. Ligand-receptor dissociation or
b. Diminished cellular pulling
c. Or the receptor / ligand complex dissociated