Self-Recognition Between Two Almost Identical Macroions During Their Assembly: The Effects of pH and Temperature

Gigantic supramolecular assemblies built from dynamic hierarchical organization between inorganic nanospheres and porphyrins

Noncovalent ionic interactions between nanosized Keplerate-type capsules {Mo₁₃₂} and tetra-cationic porphyrins have been investigated in aqueous solution using small-angle X-ray scattering, ¹H NMR and photophysical methods. These complementary multiscale methods reveal the formation of large hybrid oligomers built from a short-range organization in which the cationic porphyrin is glued onto the large POM surface. The local structuring appears to be strongly dependent on the dye : {Mo₁₃₂} ratio changing the morphology of the oligomers from linear to dense aggregates.

Rational Control of Self-Recognition of Macroionic γ-Cyclodextrin by Host-Guest Interaction with Super-Chaotropic Borate Cluster Ions

We report a feasible method to control self-recognition during the self-assembly of a hydrophilic macroion, phosphate-functionalized γ-cyclodextrin (γ-CD-P), though host-guest interactions. We confirmed that γ-CD-P can form a host-guest complex with a super-chaotropic anion, namely the B₁₂ F₁₂ ^2- borate cluster, by using NMR spectroscopy and isothermal titration calorimetry. The loaded γ-CD-P, which has a higher charge density, can be distinguished from the uncomplexed γ-CD-P, leading to self-sorting behavior during the self-assembly process, confirmed by the formation of two types of individual supramolecular structures (R_h of ca. 57 nm and 18 nm, determined by light scattering) instead of hybrid structures in mixed dilute solution. This self-recognition behavior is accounted for by the difference in intermolecular electrostatic interactions arising from the loading.

Subcellular stoichiogenomics reveal cell evolution and electrostatic interaction mechanisms in cytoskeleton

Background

Eukaryotic cells contain a huge variety of internally specialized subcellular compartments. Stoichiogenomics aims to reveal patterns of elements usage in biological macromolecules. However, the stoichiogenomic characteristics and how they adapt to various subcellular microenvironments are still unknown.

Results

Here we first updated the definition of stoichiogenomics. Then we applied it to subcellular research, and detected distinctive nitrogen content of nuclear and hydrogen, sulfur content of extracellular proteomes. Specially, we found that acidic amino acids (AAs) content of cytoskeletal proteins is the highest. The increased charged AAs are mainly caused by the eukaryotic originated cytoskeletal proteins. Functional subdivision of the cytoskeleton showed that activation, binding/association, and complexes are the three largest functional categories. Electrostatic interaction analysis showed an increased electrostatic interaction between both primary sequences and PPI interfaces of 3D structures, in the cytoskeleton.

Conclusions

This study creates a blueprint of subcellular stoichiogenomic characteristics, and explains that charged AAs of the cytoskeleton increased greatly in evolution, which offer material basis for the eukaryotic cytoskeletal proteins to act in two ways of electrostatic interactions, and further perform their activation, binding/association and complex formation.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4845-0) contains supplementary material, which is available to authorized users.