14 research outputs found
Molecularly Engineered âJanus GroELâ: Application to Supramolecular Copolymerization with a Higher Level of Sequence Control
Herein we report the synthesis and isolation of a shape-persistent Janus protein nanoparticle derived from the biomolecular machine chaperonin GroEL (^AGroEL^B) and its application to DNA-mediated ternary supramolecular copolymerization. To synthesize ^AGroEL^B with two different DNA strands A and B at its opposite apical domains, we utilized the unique biological property of GroEL, i.e., MgÂČâș/ATP-mediated ring exchange between ^AGroEL^A and ^BGroEL^B with their hollow cylindrical double-decker architectures. This exchange event was reported more than 24 years ago but has never been utilized for molecular engineering of GroEL. We leveraged DNA nanotechnology to purely isolate Janus ^AGroEL^B and succeeded in its precision ternary supramolecular copolymerization with two DNA comonomers, A** and B*, that are partially complementary to A and B in ^AGroEL^B, respectively, and programmed to self-dimerize on the other side. Transmission electron microscopy allowed us to confirm the formation of the expected dual-periodic copolymer sequence â(^(B*/B)GroEL^(A/A**/A**/A)GroEL^(B/B*))â in the form of a laterally connected lamellar assembly rather than a single-chain copolymer
Protein Nanotube Selectively Cleavable with DNA: Supramolecular Polymerization of âDNA-Appended Molecular Chaperonesâ
Here,
we report molecular chaperone GroELs that carry, at their
apical domains, multiple DNA strands (ideally 28 DNA strands in total)
with defined oligonucleotide (nt) sequences. This design strategy
allows for the preparation of <b>GroEL</b><sub><b>10a</b></sub> and <b>GroEL</b><sub><b>10b</b></sub> carrying
10-nt DNA strands of <b>10a</b> and <b>10b</b> with complementary
sequences, respectively, at their apical domains. One-dimensional
coassembly of these GroELs is possible to form protein nanotube <b>NT</b><sub><b>10a/10b</b></sub> with an anomalous thermodynamic
stability due to the exceptionally large multivalency for the coassembly.
Likewise, comparably stable nanotube <b>NT</b><sub><b>15c/10d</b></sub> was obtained even when the apical-domain DNA strands (<b>15c</b> and <b>10d</b>) were partially complementary to
one another. Nevertheless, in sharp contrast with <b>NT</b><sub><b>10a/10b</b></sub>, <b>NT</b><sub><b>15c/10d</b></sub>, when incubated with DNA <b>15d</b>, dissociates rapidly
and completely because <b>15d</b> preferentially hybridizes
with the DNA strands of <b>15c</b> in <b>NT</b><sub><b>15c/10d</b></sub> by displacing those of <b>10d</b>, to
afford a mixture of <b>GroEL</b><sub><b>15c/15d</b></sub> and <b>GroEL</b><sub><b>10d</b></sub>. Even in the presence
of <b>NT</b><sub><b>10c/10d</b></sub>, <b>15d</b> cleaved off <b>NT</b><sub><b>15c/10d</b></sub> selectively,
indicating the potential utility of <b>NT</b>s for targeted
delivery
Molecularly Engineered Janus GroEL: Application to Supramolecular Copolymerization with a Higher Level of Sequence Control
Herein we report the synthesis and isolation of a shape-persistent Janus protein nanoparticle derived from the biomolecular machine chaperonin GroEL (^AGroEL^B) and its application to DNA-mediated ternary supramolecular copolymerization. To synthesize ^AGroEL^B with two different DNA strands A and B at its opposite apical domains, we utilized the unique biological property of GroEL, i.e., MgÂČâș/ATP-mediated ring exchange between ^AGroEL^A and ^BGroEL^B with their hollow cylindrical double-decker architectures. This exchange event was reported more than 24 years ago but has never been utilized for molecular engineering of GroEL. We leveraged DNA nanotechnology to purely isolate Janus ^AGroEL^B and succeeded in its precision ternary supramolecular copolymerization with two DNA comonomers, A** and B*, that are partially complementary to A and B in ^AGroEL^B, respectively, and programmed to self-dimerize on the other side. Transmission electron microscopy allowed us to confirm the formation of the expected dual-periodic copolymer sequence â(^(B*/B)GroEL^(A/A**/A**/A)GroEL^(B/B*))â in the form of a laterally connected lamellar assembly rather than a single-chain copolymer
Expression of liver X receptors in normal and refractory carcinoma tissues of the human lung and pancreas
Liver X receptors (LXRs) participate not
only in maintaining cholesterol homeostasis but also in
controlling cellular growth in many types of normal and
tumor cells. We previously reported that LXRα was
aberrantly expressed in human oral squamous cell
carcinoma (HOSCC) tissues and cell lines, and that LXR
stimulation led to significant reduction of proliferation
of HOSCC cells via accelerating cholesterol efflux.
Since LXRs and downstream proteins involved in
cholesterol metabolism could be also applied as
therapeutic targets in small cell lung carcinoma (SCLC)
and pancreatic ductal adenocarcinoma (PDAC), we
herein analyzed the distribution of LXR proteins in these
refractory cancers as well as in normal human lung and
pancreatic tissues. LXRÎČ was observed in ciliated
epithelial cells, bronchial gland epithelia, type II alveolar
epithelia and alveolar macrophages of the lung, and was
less expressed in bronchial basal cells and type I alveolar
epithelia. In addition, LXRÎČ was detected in epithelium
of the pancreatic duct and acinar cells of the pancreas,
and was weakly expressed in pancreatic islet cells. By
contrast, LXRα expression was restricted to alveolar
macrophages, and was not evident in any types of
epithelial cells in the lung and pancreas. We also
demonstrated that LXRÎČ but not LXRα was abundantly
expressed in nine cases of SCLC and twenty cases of
PDAC tissues. These findings provide basic information
for evaluating the efficacy of LXR-targeted treatment in
SCLC and PDA
The International Linear Collider: Report to Snowmass 2021
The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in the 2030s. The ILC addresses key questions for our current understanding of particle physics. It is based on a proven accelerator technology. Its experiments will challenge the Standard Model of particle physics and will provide a new window to look beyond it. This document brings the story of the ILC up to date, emphasizing its strong physics motivation, its readiness for construction, and the opportunity it presents to the US and the global particle physics community
The International Linear Collider: Report to Snowmass 2021
International audienceThe International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in the 2030s. The ILC addresses key questions for our current understanding of particle physics. It is based on a proven accelerator technology. Its experiments will challenge the Standard Model of particle physics and will provide a new window to look beyond it. This document brings the story of the ILC up to date, emphasizing its strong physics motivation, its readiness for construction, and the opportunity it presents to the US and the global particle physics community