The spores surface display is the most ideal, with enhanced effects, low cost, less time consumption and the most beneficial technology for the development of the environment, medicine and industry. Since spores can survive harsh industrial processes, including heat resistance, alkali resistance, chemical resistance, easy recycling and reusability, they have many industrial applications. Yeast and bacteria (including gram positive and negative) are the most commonly used organisms that display various proteins (eukaryotic and prokaryotic).
Spores have the ability to survive stress conditions such as high temperature, ultraviolet radiation, enzymatic and chemical damage, and dryness. Displaying proteins and peptides on the surface of microorganisms is becoming a basic tool to overcome the problems of biological processes, harsh industrial processes, vaccine development and environmental protection processes.
Yeast is a promising tool for displaying various enzymes and proteins. Through fusion with the N-terminus of the cell wall, different types of enzymes were demonstrated and successfully immobilized on the surface of Pichia pastoris and Saccharomyces cerevisiae. Genetically engineered yeast has many applications in chemical synthesis, biotechnology production, environmental pollutant adsorption, biorefinery and protein evolution.
Bacterial spores have some unique characteristics (heat resistance, pH stability, alkali resistance), and can be used to produce oral vaccines by displaying heat-sensitive antigens on the bacterial spores to overcome the harsh environment of the stomach, and it turns out that they are very useful in such applications. The recombinant spores displayed on the surface can be used as oral vaccines, such as expressing the tetanus toxin fragment C of Clostridium tetani or the unstable thermotoxin of E. coli with serum IgG titer, which is used in the parental mouse model Induce an immunogenic response and consider oral administration.
Displaying different protein spores on Bacillus subtilis has great potential for application in protein fixation. The display of proteins on the surface of spores may cause changes in protein structure and surface charge, leading to increased relative activity, thermal stability, pH stability, and reusability.
The fusion of the carrier protein and the anchor protein directly affects the successful surface display and the activity and stability of the display protein. It is difficult to predict whether the peptide sequence (linker) will help increase the stability and activity of the protein, but unpublished data shows that the use of different peptide linkers has many effects on the activity and stability of the enzyme compared to directly anchoring the protein.
Spore surface display has many applications in the fields of industry, environment and medicine, but there are certain limitations and it is difficult to obtain ideal results. The success of displaying on the spore surface depends on the fusion of the anchor protein and the target protein, so it is becoming more and more difficult to select the correct fusion protein and anchor partner.
Due to low cost and wide application, displaying proteins and peptides on microorganisms is becoming a leading technology. Spore surface display is a multimeric strategy for vaccine production, industrial biocatalysis and certain applications in environmental protection. The use of different proteins and antigens on the surface of the spores can enhance its activity and the stability of the biodegradation of harmful compounds, and can be related to vaccine methods. In order to be successfully displayed, the chimeric protein must pass through at least one membrane. However, due to rapid folding and hydrophobic plaques, certain proteins have no crossover ability. To avoid all these problems, the best way is to use endospore-forming bacteria, such as Bacillus subtilis, because the proteins displayed on the spore surface do not need to cross the membrane barrier.
In order to enhance the enzymatic activity, researchers need to study the molecular dynamics of the desired protein and design a suitable linker for the construction of the fusion protein. The relatively flexible link between the carrier and the target protein is a better choice for the C-terminus or the N-terminus to move relatively freely to obtain a better domain. Rigid joints can maintain a certain distance in the two domains to avoid interference. Therefore, it is very important to find a suitable linker for sporessurface display.