Cage-type calix[4]pyrroles 2 and 3 bearing two additional pyrrole groups on the strap have been synthesized. Compared with the parent calix[4]pyrrole (1), they were found to exhibit remarkably enhanced affinities for anions, including the sulfate anion (TBA(+) salts), in organic media (CD2Cl2). This increase is ascribed to participation of the bipyrrole units in anion binding. Receptors 2 and 3 extract the hydrophilic sulfate anion (as the methyltrialkyl(C(8-10))ammonium (A336(+)) salt) from aqueous media into a chloroform phase with significantly improved efficiency (>10-fold relative to calix[4]pyrrole 1). These two receptors also solubilize into chloroform the otherwise insoluble sulfate salt, (TMA)2SO4 (tetramethylammonium sulfate).

Cancer cells are a major source of enzymes that modify collagen to create a stiff, fibrotic tumor stroma. High collagen lysyl hydroxylase 2 (LH2) expression promotes metastasis and is correlated with shorter survival in lung adenocarcinoma (LUAD) and other tumor types. LH2 hydroxylates lysine (Lys) residues on fibrillar collagen’s amino- and carboxy-terminal telopeptides to create stable collagen cross-links. Here, we show that electrostatic interactions between the LH domain active site and collagen determine the unique telopeptidyl lysyl hydroxylase (tLH) activity of LH2. However, CRISPR/Cas-9-mediated inactivation of tLH activity does not fully recapitulate the inhibitory effect of LH2 knock out on LUAD growth and metastasis in mice, suggesting that LH2 drives LUAD progression, in part, through a tLH-independent mechanism. Protein homology modeling and biochemical studies identify an LH2 isoform (LH2b) that has previously undetected collagen galactosylhydroxylysyl glucosyltransferase (GGT) activity determined by a loop that enhances UDP-glucose-binding in the GLT active site and is encoded by alternatively spliced exon 13 A. CRISPR/Cas-9-mediated deletion of exon 13 A sharply reduces the growth and metastasis of LH2b-expressing LUADs in mice. These findings identify a previously unrecognized collagen GGT activity that drives LUAD progression.

Parastichy, the spiral arrangement of plant organs, is an example of the long-range apparent order seen in biological systems. These ordered arrangements provide scientists with both an aesthetic challenge and a mathematical inspiration. Synthetic efforts to replicate the regularity of parastichy may allow for molecular-scale control over particle arrangement processes. Here we report the packing of a supramolecular truncated cuboctahedron (TCO) into double-helical (DH) nanowires on a graphite surface with a non-natural parastichy pattern ascribed to the symmetry of the TCOs and interactions between TCOs. Such a study is expected to advance our understanding of the design inputs needed to create complex, but precisely controlled, hierarchical materials. It is also one of the few reported helical packing structures based on Platonic or Archimedean solids since the discovery of the Boerdijk–Coxeter helix. As such, it may provide experimental support for studies of packing theory at the molecular level.

Different pyridine dipyrrolate cages including cage-based dimers and polymers may be fabricated in a controlled manner from the same two starting materials, namely, an angular ligand 1 and Zn­(acac)2, by changing the counter cation source. With tetrabutylammonium (TBA+) and dimethyl viologen (DMV2+), Cage-3 and Cage-5 are produced. In these cages, two ligands act as bridges and serve to connect together two cage subunits to produce higher order ensembles. In Cage-3 and Cage-5, the TBA+ and DMV2+ counter cations lie outside the cavities of the respective cages. This stands in contrast to what is seen with a previously reported system, Cage-1, wherein dimethylammonium (DMA+) counter cations reside within the cage cavity. When the counter cations are tetraethylammonium (TEA+) and bis­(cyclopentadienyl) cobalt­(III) (Cp2Co+), polymeric cage materials, PC-1 and PC-2, are formed, respectively. The counter cations thus serve not only to balance charge but also to tune the structural features as a whole. The organic cations used in the present study also act to modulate the further assembly of individual cages. The present cation-based tuning emerges as a new method for a fine-tuning of the multidimensional morphology of self-assembled inorganic materials.