RESUMEN
The leukocyte common antigen CD45 is a receptor tyrosine phosphatase and one of the most prevalent antigens found on the surface of blood cells. CD45 plays a crucial role in the initial stages of signal transmission from receptors of various immune cell types. Immunodeficiency, autoimmune disorders, and oncological diseases are frequently caused by gene expression disorders and imbalances in CD45 isoforms. Despite extensive research into the structure and functions of CD45, the molecular mechanisms behind its role in transmitting signals from T-cell receptors and chimeric antigen receptors remain not fully understood. It is of utmost importance to comprehend the structural features of CD45 and its function in regulating immune system cell activation to study oncological diseases and the impact of CD45 on lymphocytes and T cells modified by chimeric antigen receptors.
RESUMEN
It was demonstrated that crystals of entomopathogenic protein from Bac. thuringiensis contain admixture of proteinase either adhered to their surface on inconponated into crystal lattice defects. A proteolytic action, particularly when enhanced by crystal dissolution, causes progressive degradation of crystal proteins with molecular weights of 140 000--129 000 down to the components with smaller molecular weights. This may, at least, partially account for the contradictions in the literature data on crystal composition. Using synthetic peptide substrates and specific inhibitors, it was shown that the enzymes incorporated into crystals belong to serine and metalloproteases. The presence of leucine aminopeptidase was also noted. A method for enzyme separation from crystal has been developed.
