Biology subjects

Deich, C.

Publications and source records attributed to Deich, C..

3 recordsLinked to original sources

bioRxiv2022

Controlled exchange of protein and nucleic acid signals from and between synthetic minimal cells

Synthetic minimal cells are a class of small liposome bioreactors that have some, but not all functions of live cells. Here, we report a critical step towards the development of a bottom-up minimal cell: cellular export of functional protein and RNA products. We used cell penetrating peptide tags to translocate payloads across a synthetic cell vesicle membrane. We demonstrated efficient transport of active enzymes, and transport of nucleic acid payloads by RNA binding proteins. We investigated influence of a concentration gradient alongside other factors on the efficiency of the translocation, and we show a method to increase product accumulation in one location. We demonstrate the use of this technology to engineer molecular communication between different populations of synthetic cells, to exchange protein and nucleic acid signals. The synthetic minimal cell production and export of proteins or nucleic acids allows experimental designs that approach the complexity and relevancy of natural biological systems.

synthetic biology↗

bioRxiv2021

Akaby - cell-free protein expression system for linear templates

Cell-free protein expression is increasingly becoming popular for biotechnology, biomedical and research applications. Among cell-free systems, the most popular one is based on Escherichia coli (E. coli). Endogenous nucleases in E. coli cell-free transcription-translation (TXTL) degrade the free ends of DNA, resulting in inefficient protein expression from linear DNA templates. RecBCD is a nuclease complex that plays a major role in nuclease activity in E. coli, with the RecB subunit possessing the actual nuclease activity. We created a RecB knockout of an E. coli strain optimized for cell-free expression. We named this new strain Akaby. We demonstrated that Akaby TXTL successfully reduced linear DNA degradations, rescuing the protein expression efficiency from the linear DNA templates. The practicality of Akaby for TXTL is an efficient, simple alternative for linear template expression in cell-free reactions. We also use this work as a model protocol for modifying the TXTL source E. coli strain, enabling the creation of TXTL systems with other custom modifications.

synthetic biology↗

bioRxiv2021

T7Max transcription system

Efficient cell-free protein expression from linear DNA templates has remained a challenge primarily due to template degradation. Here we present a modified T7 RNA polymerase promoter that acts to significantly increase the yields of both transcription and translation within in vitro systems. The modified promoter, termed T7Max, recruits standard T7 RNA polymerase, so no protein engineering is needed to take advantage of this method. This technique could be used with any T7 RNA polymerase-based in vitro protein expression system. Unlike other methods of limiting linear template degradation, the T7Max promoter increases transcript concentration in a T7 transcription reaction, providing more mRNA for translation.

synthetic biology↗