Abstract
Didelphis aurita is a synanthropic marsupial widely distributed in southeastern Brazil, known for its resistance to venom and its relevance in biomedical research. This study aimed to characterize the serum proteinogram of free-living D. aurita individuals. Blood samples from 27 animals, classified as "healthy" or "diseased," were analyzed. Eighteen protein bands were identified, with molecular weights ranging from 24 to 242 kDa. Among these, variations in specific bands were associated with health status (band J), sex (bands D, M, N, and P), and age (bands N and P). Mass spectrometry (liquid chromatography-tandem mass spectrometry [LC-MS/MS]) identified seven proteins, including DM64, ceruloplasmin, von Willebrand factor A (VWFA) domain protein, alpha-2-macroglobulin, fibronectin, and actin depolymerizing factor. These results highlight the influence of biological factors on serum protein profiles and reinforce the potential of D. aurita as a model for immunological and proteomic studies.