Analyzing The Specificity Of Proteasome Cleaves Site To Antigenic Protein By Independent Component Analysis Method

Human bodies are constantly threatened by billions of potential pathogens,such asbacteria,viruses,fungi and parasites.Therefore,our multi-layered defense has evolved into a complex mechanism to protect the human body from these pathogens.Physical and chemical barriers,such as skin or stomach fluids,are major nonspecific barriers to prevent pathogens from entering host organisms.CD8+T lymphocytes are specific immune cells,which mediate an effective immune response to tumors.CD8+T cells can also recognize and remove these virus cells.The major histocompatibility complex expressed on the cell surface,MHC I(major histocompatibility complex)molecules transfer antigen peptides to the outside world,enabling them to be specifically identified by cytotoxic T lymphocytes(CTLs).These special T cells can detect other cells that express foreign or abnormal(i.e.,mutant)protein molecules and then remove these extra cells from the body.These antigenic peptides requires 26 s proteasome to degrade antigenic proteins,forming the size of peptide fragment that is suitable for transportation,they need TAP(transporter associated with antigen processing)molecular to transport to ER(endoplasmic reticulum)and combine with the MHC class I molecule binding groove.In the process of immunization,T cells initiate the immune response mainly through T cell receptors(TCR)recognizing antigen peptides.In this study,these antigen peptides were found from immune resource databases,and were constituted positive and negative samples of the proteasome cleavage sites from these source proteins.Fast ICA method on negative entropy was used to establish a proteasome cleavage site prediction model,and this model has the prediction accuracy of 70.86%.It compares with other models in the literature under the same data,and it has better results.In addition,it can be seen that proteasome is selective in the antigen-protein cleavage site,through the analysis of proteasome structure,and the specificity of the cleavage site has been analyzed and discussed.