PPID (Peptidyl-Prolyl Isomerase D), also known as Cyclophilin D (CypD), is a mitochondrial protein belonging to the cyclophilin family. It functions as a chaperone, facilitating protein folding via its peptidyl-prolyl cis-trans isomerase activity. PPID is critically involved in regulating the mitochondrial permeability transition pore (mPTP), a key mediator of cell death pathways. Dysregulation of PPID has been linked to pathologies such as ischemia-reperfusion injury, neurodegenerative diseases, and cancer.
Antibodies targeting PPID are essential tools for studying its expression, localization, and interactions. They enable detection in techniques like Western blotting, immunohistochemistry, and immunofluorescence. Research using PPID antibodies has elucidated its role in apoptosis, calcium homeostasis, and oxidative stress responses. Notably, PPID's interaction with the mPTP makes it a therapeutic target; inhibitors like cyclosporine A bind to PPID to modulate mPTP opening.
Recent studies explore PPID's dual roles in promoting cell survival under stress and triggering death signals during injury. Its tissue-specific expression patterns and post-translational modifications further underscore its regulatory complexity. PPID antibodies thus remain vital for advancing understanding of mitochondrial biology and developing treatments for related disorders.