Aminopeptidase A (APA), also known as CD249 or angiotensinase, is a membrane-bound metalloprotease belonging to the M1 family of zinc-dependent enzymes. It catalyzes the cleavage of N-terminal acidic residues from peptides, notably converting angiotensin II to angiotensin III, thereby playing a role in blood pressure regulation and the renin-angiotensin system. APA is expressed on the surface of various cell types, including renal proximal tubules, vascular endothelial cells, and specific immune cells.
Antibodies targeting APA/CD249 are essential tools for studying its expression, localization, and function in physiological and pathological contexts. In research, these antibodies are utilized in techniques such as immunohistochemistry, flow cytometry, and Western blotting to investigate APA's involvement in hypertension, inflammation, and cancer. For example, elevated APA levels have been linked to tumor progression in certain cancers, such as glioblastoma, where it may influence angiogenesis and immune evasion.
Additionally, APA's role in modulating bioactive peptides highlights its potential as a therapeutic target. Anti-APA antibodies have been explored in preclinical studies for conditions like preeclampsia and hypertension. Understanding APA's regulatory mechanisms and tissue-specific expression through antibody-based assays continues to advance insights into its dual roles in homeostasis and disease, underscoring its relevance in both basic research and clinical applications.