Recombinant Human AHNAK protein

AHNAK, originally identified as a giant protein (∼700 kDa) encoded by the AHNAK gene, plays multifaceted roles in cellular processes, including cell membrane repair, cytoskeletal organization, and calcium signaling regulation. Initially discovered as a tumor suppressor linked to neuroblastoma differentiation, AHNAK has since been implicated in diverse physiological and pathological contexts, such as cancer metastasis, cardiovascular function, and muscular dystrophy. Structurally, AHNAK contains a central repetitive domain flanked by N- and C-terminal globular regions, enabling interactions with proteins like annexins, dysferlin, and calmodulin, which underpin its functional versatility.

Recombinant AHNAK proteins are engineered to study domain-specific interactions and mechanistic pathways. These proteins are typically expressed in heterologous systems (e.g., E. coli, mammalian cells) using truncated constructs due to AHNAK's enormous size. Purification often involves affinity tags (e.g., His-tag, GST) followed by chromatographic techniques. Recombinant AHNAK fragments have been instrumental in elucidating its role in calcium-dependent membrane repair—by bridging vesicle fusion sites—and in modulating ion channel activity (e.g., L-type calcium channels in cardiomyocytes). In cancer, recombinant domains help dissect AHNAK's paradoxical roles: while full-length AHNAK may suppress tumor invasion, proteolytic cleavage generates fragments that promote metastasis via EGFR or TGF-β signaling.

Challenges in working with recombinant AHNAK include maintaining solubility and avoiding aggregation due to its intrinsically disordered regions. Despite this, such tools remain vital for developing therapeutic strategies, particularly in diseases involving membrane instability or dysregulated calcium homeostasis. Ongoing research leverages these proteins to design peptide inhibitors or biomarkers targeting AHNAK-associated pathways in cancer and muscular disorders.