The Amblyomin-X is a Kunitz-type inhibitor that was identified in the transcriptome of Amblyomma cajennense through analysis of ESTs sequences from a cDNA library, was expressed with a 6xHis-Tag fused at its N-terminus in E. coli, representing a protein with 13.4 kDa, with a single single chain protein that contains seven cysteine residues. This protein is is able to inhibit FXa activity in the presence of phospholipids and to prolong coagulation times overall as the activated partial thromboplastin time (APTT), prothrombin time (PT) and the PCA test - analysis of activity pro -coagulant. It was recently shown that the Amblyomin-X has pro-apoptotic activity in tumor cells and in vivo experiments, promotes regression of tumor mass and reduction of metastasis of some tumors tested. In vitro experiments showed that Amblyomin-X is able to inhibit the proteasome in tumor cells, increasing the pool of poly-ubiquitinated proteins, suggesting a possible disturbance of homeostasis of the endoplasmic reticulum (ER), which could be correlated with their pro-apoptotic effect. Thus, the purpose of this study is to investigate the internalization of Amblyomin-X by normal and tumor cells, as well as its structural state after this event and to correlate these results with the inhibition of proteasome caused by this protein, and to evaluate whether this effect promotes inhibition of ER stress, evaluating ways and marker proteins of this type of mechanism.
News published in Agência FAPESP Newsletter about the scholarship: