Phase separation and selective guest–host binding in multi-component supramolecular self-assembly on Au(111)

Block polymer membranes in the hollow fiber geometry were fabricated by combining the dip-coating archetype with the self-assembly and non-solvent induced phase separation method.

Download Full-text

Phase Separation of Shell Protein and Enzyme: An Insight into the Biogenesis of a Prokaryotic Metabolosome

10.1101/2022.01.14.476392 ◽

2022 ◽

Author(s):

Gaurav Kumar ◽

Sharmistha Sinha

Keyword(s):

Phase Separation ◽

Protein Interactions ◽

Self Assembly ◽

Bacterial Species ◽

Protein Structures ◽

The Self ◽

Liquid Droplets ◽

Shell Protein ◽

Shell Proteins

Bacterial microcompartments are substrate specific metabolic modules that are conditionally expressed in certain bacterial species. These all protein structures have size in the range of 100-150 nm and are formed by the self-assembly of thousands of protein subunits, all encoded by genes belonging to a single operon. The operon contains genes that encode for both enzymes and shell proteins. The shell proteins self-assemble to form the outer coat of the compartment and enzymes are encapsulated within. A perplexing question in MCP biology is to understand the mechanism which governs the formation of these small yet complex assemblages of proteins. In this work we use 1,2-propanediol utilization microcompartments (PduMCP) as a paradigm to identify the factors that drive the self-assembly of MCP proteins. We find that a major shell protein PduBB tend to self-assemble under macromolecular crowded environment and suitable ionic strength. Microscopic visualization and biophysical studies reveal phase separation to be the principle mechanism behind the self-association of shell protein in the presence of salts and macromolecular crowding. The shell protein PduBB interacts with the enzyme diol-dehydratase PduCDE and co-assemble into phase separated liquid droplets. The co-assembly of PduCDE and PduBB results in the enhancement of catalytic activity of the enzyme. A combination of spectroscopic and biochemical techniques shows the relevance of divalent cation Mg2+ in providing stability to intact PduMCP in vivo. Together our results suggest a combination of protein-protein interactions and phase separation guiding the self-assembly of Pdu shell protein and enzyme in solution phase.

Download Full-text

Critical contributions of additive directed fabrication of isoporous membranes via the self-assembly and non-solvent induced phase separation: A review

Chemical Engineering Journal ◽

10.1016/j.cej.2021.128912 ◽

2021 ◽

pp. 128912

Author(s):

Cao-ying Yang ◽

Guo-dong Zhu ◽

Zhuan Yi ◽

Cong-jie Gao

Keyword(s):

Phase Separation ◽

Self Assembly ◽

The Self

Download Full-text

A Comparative Study of the Phase Separation of a Nematic Liquid Crystal in the Self-assembling Drying Protein Drops

MRS Advances ◽

10.1557/adv.2019.209 ◽

2019 ◽

Vol 4 (22) ◽

pp. 1309-1314 ◽

Cited By ~ 2

Author(s):

Anusuya Pal ◽

Amalesh Gope ◽

Germano S. Iannacchione

Keyword(s):

Liquid Crystal ◽

Phase Separation ◽

Self Assembly ◽

Intensity Variation ◽

The Self ◽

Drying Process ◽

Bright Region ◽

Self Assembling ◽

Initial Aqueous Solution ◽

Significant Difference

ABSTRACTThe drying process, self-assembly of the proteins and the phase separation of a thermotropic liquid crystal (LC) from an initial aqueous solution represent a rich area of study. A focus of this work is to compare the behavior of two different proteins, bovine serum albumin [BSA] and lysozyme [Lys] in the ternary system through optical microscopy. During the drying process, the intensity profile shows three regimes in the presence of LC whereas no intensity variation is observed in its absence in both protein drops. The striking outcome is the presence of an umbilical defect of [+1] strength in every domain near the edge of BSA drop, whereas, each domain has a central dark region surrounded by a bright region in the dried Lys drop. Finally, the crack spacing in the dried Lys drop is reduced in the presence of LC whereas, no significant difference is found in the dried BSA drop.

Download Full-text

Study on Structure of the New Polymer-Poly (Propylene-Co-γ-Butyrolactone Carbonate) with Molecular Model

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.3076 ◽

2007 ◽

Vol 353-358 ◽

pp. 3076-3079

Author(s):

Ling Bin Lu ◽

Ke Long Huang ◽

Feng Wen

Keyword(s):

Phase Separation ◽

Self Assembly ◽

Molecular Model ◽

The Self ◽

Molecular Chain ◽

Drug Molecule ◽

Carboxylic Ester ◽

Poly Propylene ◽

The Relationship ◽

Materials Studio

Based on COMPASS forcefield, the relationship between microstructure and macroscopic properties of poly (propylene-co-γ-butyrolactone carbonate) (PPCG) was firstly investigated with ‘Materials Studio’ simulation soft successfully. The results of simulation showed that the molecular chain of PPCG was flexible. Degradable carbonic and carboxylic ester groups were distributed outside the PPCG cell. Furthermore the structure of micro-phase separation was observed in PPCG cell. The structure of micro-phase separation of PPCG can be applied to the self-assembly of drug molecule.

Download Full-text