Three- and Eight-Fold Interpenetrated ThSi₂ Metal–Organic Frameworks Fine-Tuned by the Length of Ligand

Two new interpenetrated ThSi₂ networks, {[Ag₄(bipy)₄(ox)]·2OH·16H₂O}_<i>n</i> (<b>1</b>) and {[Ag₂(dpb)₂(ox)]·10H₂O}_<i>n</i> (<b>2</b>) (bipy = 4,4′-bipyridine, dpb = 1,4-di­(pyridin-4-yl)­benzene and Na₂ox = sodium oxalate), were constructed from bidentate pyridyl-based organic tectons incorporating ox auxiliary ligand. Interestingly, both <b>1</b> and <b>2</b> are 3D frameworks with the same ThSi₂ topology but with substantial changes in the interpenetration degrees, which are well controlled by employing the pyridyl-based ligands with different lengths. The thermal stabilities and photoluminescence behaviors of them were also discussed

Three- and Eight-Fold Interpenetrated ThSi₂ Metal–Organic Frameworks Fine-Tuned by the Length of Ligand

Two new interpenetrated ThSi₂ networks, {[Ag₄(bipy)₄(ox)]·2OH·16H₂O}_<i>n</i> (<b>1</b>) and {[Ag₂(dpb)₂(ox)]·10H₂O}_<i>n</i> (<b>2</b>) (bipy = 4,4′-bipyridine, dpb = 1,4-di­(pyridin-4-yl)­benzene and Na₂ox = sodium oxalate), were constructed from bidentate pyridyl-based organic tectons incorporating ox auxiliary ligand. Interestingly, both <b>1</b> and <b>2</b> are 3D frameworks with the same ThSi₂ topology but with substantial changes in the interpenetration degrees, which are well controlled by employing the pyridyl-based ligands with different lengths. The thermal stabilities and photoluminescence behaviors of them were also discussed

DataSheet_1_Amide-containing neoepitopes: the key factor in the preparation of hapten-specific antibodies and a strategy to overcome.docx

For a long time, people have suffered from uncertainty, complexity, and a low success rate in generating and screening antibodies against small molecules, which have become the core bottlenecks of immunochemistry. Here, the influence of antigen preparation on antibody generation was investigated at both molecular and submolecular levels. Neoepitopes (amide-containing neoepitopes) formed in the preparation of complete antigens are one of the most important factors limiting the efficiency of generating hapten-specific antibodies, which was verified by different haptens, carrier proteins, and conjugation conditions. Amide-containing neoepitopes present electron-dense structural components on the surface of prepared complete antigens and, therefore, induce the generation of the corresponding antibody with much higher efficiency than target hapten. Crosslinkers should be carefully selected and not overdosed. According to these results, some misconceptions in the conventional anti-hapten antibody production were clarified and corrected. By controlling the content of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) during the synthesis of immunogen to limit the formation of amide-containing neoepitopes, the efficiency of hapten-specific antibody generation could be significantly improved, which verified the correctness of the conclusion and provided an efficient strategy for antibody preparation. The result of the work is of scientific significance in the preparation of high-quality antibodies against small molecules.</p

Principles of Inter-Amino-Acid Recognition Revealed by Binding Energies between Homogeneous Oligopeptides

We have determined the interaction strengths of the common naturally occurring amino acids using a complete binding affinity matrix of 20 × 20 pairs of homo-octapeptides consisting of the 20 common amino acids between stationary and mobile states. We used a bead-based fluorescence assay for these measurements. The results provide a basis for analyzing specificity, polymorphisms, and selectivity of inter-amino-acid interactions. Comparative analyses of the binding energies, i.e., the free energies of association (ΔGA), reveal contributions assignable to both main-chain-related and side-chain-related interactions originating from the chemical structures of these 20 common amino acids. Side-chain–side-chain and side-chain–main-chain interactions are found to be pronounced in an identified set of amino acid pairs that determine the basis of inter-amino-acid recognition