Multi-Responsive Wrinkling Patterns by the Photoswitchable Supramolecular Network

Multiresponsive reversible wrinkling patterns provide an effective approach to dynamically tuning the properties of surface on-demand to realize a smart surface; however, their fabrication remains challenging. In this study, we report a simple yet robust method to fabricate multiresponsive wrinkles based on a supramolecular polymer network composed of copolymer (P4VP-PS-PnBA) and carboxyl containing anthracene (AN-COOH), which can be cross-linked dynamically through reversible photodimerization of anthracene (AN) and the hydrogen bond between carboxyl and pyridine groups. The wrinkle pattern can be generated and erased selectively by UV radiation of different wavelengths due to reversible dimerization of AN. The resulting wrinkles have an extremely sensitive response to hydrogen chloride (HCl) gas and can be erased by HCl with a concentration of 5 ppm in the atmosphere. The generation/elimination process responsive to light and HCl could be cycled many times without damaging characteristic wrinkles, which enables this dynamic wrinkle pattern to be employed for such potential applications as smart displays and nonink printing

Multi-Responsive Wrinkling Patterns by the Photoswitchable Supramolecular Network

Multiresponsive reversible wrinkling patterns provide an effective approach to dynamically tuning the properties of surface on-demand to realize a smart surface; however, their fabrication remains challenging. In this study, we report a simple yet robust method to fabricate multiresponsive wrinkles based on a supramolecular polymer network composed of copolymer (P4VP-PS-PnBA) and carboxyl containing anthracene (AN-COOH), which can be cross-linked dynamically through reversible photodimerization of anthracene (AN) and the hydrogen bond between carboxyl and pyridine groups. The wrinkle pattern can be generated and erased selectively by UV radiation of different wavelengths due to reversible dimerization of AN. The resulting wrinkles have an extremely sensitive response to hydrogen chloride (HCl) gas and can be erased by HCl with a concentration of 5 ppm in the atmosphere. The generation/elimination process responsive to light and HCl could be cycled many times without damaging characteristic wrinkles, which enables this dynamic wrinkle pattern to be employed for such potential applications as smart displays and nonink printing

RlmCD belongs to the RFM family of MTases.

<p>(A) The canonical topology diagram of the catalytic domain in the RFM family of MTases. (B) Cartoon representation of the catalytic domain in RlmCD (residue 286–454). SAH is shown as ball-and-stick model. (C) The topology diagram of the catalytic domain in RlmCD. An extra α-helix (α5) is formed at the C-terminus of the catalytic domain.</p

Structural insights into substrate selectivity of ribosomal RNA methyltransferase RlmCD

<div><p>RlmCD has recently been identified as the S-adenosyl methionine (SAM)-dependent methyltransferase responsible for the formation of m⁵U at U747 and U1939 of 23S ribosomal RNA in <i>Streptococcus pneumoniae</i>. In this research, we determine the high-resolution crystal structures of apo-form RlmCD and its complex with SAH. Using an in-vitro methyltransferase assay, we reveal the crucial residues for its catalytic functions. Furthermore, structural comparison between RlmCD and its structural homologue RumA, which only catalyzes the m⁵U1939 in <i>Escherichia coli</i>, implicates that a unique long linker in the central domain of RlmCD is the key factor in determining its substrate selectivity. Its significance in the enzyme activity of RlmCD is further confirmed by in-vitro methyltransferase assay.</p></div

The 23S rRNA helix 35 is the substrate of RlmCD.

<p>(A) Secondary structures of the 18-mer RNA fragments of the <i>S</i>. <i>pneumoniae</i> (left) and <i>E</i>.<i>coli</i> (right) 23S rRNA helix 35. (B) In-vitro methyltransferase assay of RlmCD. The left three columns represent the methyl transfer activities of the wild-type RlmCD or its mutants toward rRNA-h35. The right three columns represent the methyl transfer activities of the wild-type RlmCD toward the different derivatives of rRNA-h35 (U747A, U747G, and U747C).</p

SAH binds RlmCD at a canonical binding pocket.

<p>(A) The overview of SAH anchored onto the catalytic domain of RlmCD. RlmCD is shown in its electrostatic surface potential, and SAH is shown as ball-and-stick model. (<i>Inset</i>) A close-up of the engagement of SAH into the binding pocket. (B) The interaction details of SAH with RlmCD. RlmCD residues are colored in gray and SAH is colored in green. The gray mesh represents 2Fo-Fc calculated at 1σ density map of SAH and the dashed lines represent the hydrogen bonds.</p

RlmCD is a 23S rRNA methyltransferase.

<p>(A) Comparison of the MTase activities of wild-type RlmCD and its mutants using rRNA-h35 as the substrate. (B) Comparison of the MTase activities of RlmCD toward U747 and U1939. The MTase activity of wild-type RlmCD was normalized to 100%.</p

Overall structure of RlmCDs.

<p>(A) Three distinct parts of RlmCDs: the N-terminal TRAM domain, central domain, and C-terminal catalytic domain are colored in blue, green, and orange, respectively. The regions separating the three domains are all colored in grey. (B) The structure superimposition of RlmCDs and RumA (PDB ID 1UWV). RlmCDs and RumA are colored in gray and orange, respectively. (<i>Inset</i>) The superimposition of the central domain is individually shown to highlight the major difference between two structures. (C) The linker A and B of RlmCDs are shown in sticks as well as their electron density map with 2Fo-Fc calculated at 1σ.</p

Additional file 3 of Exploring the role and mechanism of Fuzi decoction in the treatment of osteoporosis by integrating network pharmacology and experimental verification

Additional file 3. The gene targets of osteoporosis

Additional file 2 of Exploring the role and mechanism of Fuzi decoction in the treatment of osteoporosis by integrating network pharmacology and experimental verification

Additional file 2. The targets of the herbs