Background:Cancer is a leading cause of death and a significant public health
issue worldwide. Standard treatment methods such as chemotherapy, radiotherapy, and
surgery are only sometimes effective. Therefore, new therapeutic approaches are needed
for cancer treatment. Sea anemone actinoporins are pore-forming toxins (PFTs) with
membranolytic activities. RTX-A is a type of PFT that interacts with membrane phospholipids,
resulting in pore formation. The synthesis of recombinant proteins in a secretory
form has several advantages, including protein solubility and easy purification. In this
study, we aimed to discover suitable signal peptides for producing RTX-A in Bacillus
subtilis in a secretory form.Methods:Signal peptides were selected from the Signal Peptide Web Server. The probability
and secretion pathways of the selected signal peptides were evaluated using the
SignalP server. ProtParam and Protein-sol were used to predict the physico-chemical
properties and solubility. AlgPred was used to predict the allergenicity of RTX-A linked
to suitable signal peptides. Non-allergenic, stable, and soluble signal peptides fused to
proteins were chosen, and their secondary and tertiary structures were predicted using
GOR IV and I-TASSER, respectively. The PROCHECK server performed the validation
of 3D structures.Results:According to bioinformatics analysis, the fusion forms of OSMY_ECOLI and
MALE_ECOLI linked to RTX-A were identified as suitable signal peptides. The final
proteins with signal peptides were stable, soluble, and non-allergenic for the human body.
Moreover, they had appropriate secondary and tertiary structures.Conclusion:The signal above peptides appears ideal for rationalizing secretory and soluble
RTX-A. Therefore, the signal peptides found in this study should be further investigated
through experimental researches and patents.