Ensaios de degradação forçada e degradação em plasma sanguíneo de peptídeos intracelulares com potencial para composição farmacológica

Abstract

Several proteins that act in the control of the cell cycle are degraded by the ubiquitin proteasome system UPS. Among them, cyclin D2, which is the precursor protein of pep5, an intracellular peptide with potential for the pharmacological composition of antitumor drugs and in combating Chagas disease. Previous studies have characterized pep5 and its minimal sequence with pharmacological action, that is, the smallest portion of the molecule without losing its therapeutic effect. The objective of this work was accomplishing tests to understand the stability profile of this promising molecule and its minimum sequence with six residues (pep5r) with pharmacological action. For this, we employ a method of forced degradation analysis in which we promote stressful situations, such as oxidation, temperature and hydrolysis to determine the degradation times under common conditions during the conditioning and transport of these peptides, in addition to these experiments, we carried out a profile study degradation of peptides in interaction with human blood plasma. The results showed that pep5r is more stable than pep5 among the parameters analyzed, in addition, pep5 was more susceptible to modification by hydrolysis in alkaline media. Both peptides did not undergo thermal modification at 37 ° for 4 hours of incubation, requiring a prolonged study or with higher temperature values to promote degradation. The degradation tests in plasma showed that pep5 is not whole after 15 minutes in interaction with human blood plasma, in contrast, the mass of pep5r was found throughout the analysis period. Therefore, we conclude that although the experiments were carried out with only one sample, the results enabled us to construct initial ideas about some characteristics related to the stability of these peptides, either by environmental actions or degradation in blood plasma. Furthermore, all the initial tests carried out in this work provide guidance for future tests aiming at an eventual pharmacological record of the peptides in question.