Proceedings of the 47th Annual Meeting of the Brazilian Biophysical Society

Annexins, proteins that bind to phospholipids in a calcium-dependent manner, are essential for the health and homeostasis of the body. They are directly involved in several biological processes, such as anti-coagulation, cell signaling, cell growth regulation, apoptosis, inflammation, vesicle fusion and intracellular transport. In this project, our focus is on Annexin A11 (AnxA11), a vital member of the annexin family. AnxA11 is associated with diverse medical conditions, including systemic autoimmune diseases and sarcoidosis. In addition, alterations in these proteins have been linked to the development of several types of cancer, chemotherapy resistance and tumor recurrence. Recently, it was discovered that multiple genetic mutations at residue D40 in AnxA11 are frequently found in patients with Amyotrophic Lateral Sclerosis. These mutant proteins form intracellular aggregates and interfere with the interaction pattern with molecular partners. In this project, we propose to elucidate the molecular details of how the D40G mutation affects the biophysical and biochemical properties of AnxA11. The full-length AnxA11 is predominantly insoluble when expressed using conventional methodologies in E.coli. We successfully developed a procedure for expressing and purifying the full-length AnxA11 with the enhanced GFP at the C-terminus. We further optimized the protein expression by using an auto-induction protocol for protein expression. The mutant D40G was created using standard molecular biology protocols for site-directed mutagenesis. Our objective is to enhance our understanding of the pathology development caused by this inherited mutation. Additionally, we aim to delineate the characteristics of the aggregates formed by this mutation.