Polyacrylate Backbone Promotes Photoinduced Reversible Solid-To-Liquid Transitions of Azobenzene-Containing Polymers

The development of polymers with efficient photoinduced reversible solid-to-liquid transitions is desirable for the design of healable materials, reconfigurable devices, and switchable adhesives. Herein, we demonstrate that an azobenzene-containing polyacrylate P-H exhibits more efficient photoinduced reversible solid-to-liquid transitions than its polymethacrylate analogue P-Me. The side chain of P-H or P-Me contains a hexamethylene spacer, a photoresponsive azobenzene group, and an n-decyl tail. Both P-H and P-Me show reversible cis–trans photoisomerization. Solid transP-H and P-Me change to liquid cis ones via UV-light-induced trans-to-cis isomerization; liquid cisP-H and P-Me revert to solid trans ones via visible-light-induced cis-to-trans back isomerization. Differential scanning calorimetry and rheology measurements revealed that photoinduced reversible solid-to-liquid transitions occur because P-H and P-Me have photoswitchable glass transition temperatures. Although P-Me exhibits a slightly faster rate for trans-to-cis photoisomerization than P-H due to fewer aggregates in solid state, cisP-H flows 20 times faster than cisP-Me because P-H has a more flexible polymer backbone. The low viscosity of cisP-H makes photoinduced solid-to-liquid transition efficient and enables the design of rapidly healable coatings. Our study shows that the design of a flexible backbone is a new strategy to develop rapidly healable polymers with more efficient photoinduced solid-to-liquid transitions

Binding sites between Fe-protein and MoFe-protein.

<p>Binding sites inferred on α (a) and β (b) subunits of MoFe protein, PDB chain 1MIO_A and 1MIO_B respectively. Two helical regions assumed to be critical for interaction are shown in magenta. Binding site residues are shown by side chains (in red color) and match with residues predicted by Kim at al. Binding site residues shown in yellow on α subunit (1MIO_A) are part of inserted 50 residues sequence and are not predicted by IBIS.</p

Reconstructing biounits by homology inference.

<p>Recovery of those homooligomeric interfaces by IBIS which can only be produced by applying crystallographic symmetry operations to PDB ASU. Recovery rate is calculated as a number of binding site residues identified by both PISA and IBIS divided by the number of binding site residues identified by PISA by applying crystallographic symmetry operations.</p

Comparison of IBIS with other protein-protein interaction prediction methods.

<p>Here N_p and N_c represent the number of total and correctly predicted binding site residues respectively. N_t is the number of true binding site residues. HomPPI was queried using the test set of 188 chains. Note that IBIS was able to make predictions for only 146 chains, as for the remaining 25 cases there were no homologous structural complexes above the 30% identity cutoff. For these 25 cases we considered the number of correctly predicted binding site residues to be zero penalizing the estimated IBIS accuracy even though by definition IBIS could not provide predictions for these cases.</p

Specificity and sensitivity of IBIS to predict protein-protein interaction.

1<p>Specificity drops to 67% when interactions from singleton clusters are also considered.</p>2<p>Sensitivity drops to 68% when interactions from only conserved clusters are considered.</p

Overview of IBIS.

<p>Overview of IBIS.</p

Percentage and frequency of CDD annotated binding sites predicted by IBIS at a given rank.

<p>Percentage and frequency of CDD annotated binding sites predicted by IBIS at a given rank.</p

Additional file 3 of SynBioTools: a one-stop facility for searching and selecting synthetic biology tools

Additional file 3. The list of reviews used for the tool and tool information extraction

Additional file 2 of SynBioTools: a one-stop facility for searching and selecting synthetic biology tools

Additional file 2. The code zip file on extracting tabular information from papers by paring the full-text XML file

Additional file 1 of SynBioTools: a one-stop facility for searching and selecting synthetic biology tools

Additional file 1. The code zip file on extracting tabular information from papers in PDF format based on OCR