Alpha 1 Antichymotrypsin (SERPINA3) Antibody – Mouse Monoclonal

The protein encoded by this gene is a plasma protease inhibitor and member of the serine protease inhibitor class. Polymorphisms in this protein appear to be tissue specific and influence protease targeting. Variations in this protein's sequence have been implicated in Alzheimer's disease, and deficiency of this protein has been associated with liver disease. Mutations have been identified in patients with Parkinson disease and chronic obstructive pulmonary disease. [provided by RefSeq]

Function: Although its physiological function is unclear, it can inhibit neutrophil cathepsin G and mast cell chymase, both of which can convert angiotensin-1 to the active angiotensin-2. Ref.14

Subunit structure: Interacts with DNAJC1. Ref.18

Subcellular location: Secreted.

Tissue specificity: Plasma. Synthesized in the liver. Like the related alpha-1-antitrypsin, its concentration increases in the acute phase of inflammation or infection. Found in the amyloid plaques from the hippocampus of Alzheimer disease brains. Ref.7 Ref.8

Domain: The reactive center loop (RCL) extends out from the body of the protein and directs binding to the target protease. The protease cleaves the serpin at the reactive site within the RCL, establishing a covalent linkage between the carboxyl group of the serpin reactive site and the serine hydroxyl of the protease. The resulting inactive serpin-protease complex is highly stable.

Miscellaneous: Alpha-1-antichymotrypsin can bind DNA.

Sequence similarities: Belongs to the serpin family.

Caution: It is uncertain whether Met-1 or Met-4 is the initiator.

Sequence caution: The sequence AAA51543.1 differs from that shown. Reason: Frameshift at positions 101, 106, 111, 117, 123, 129 and 421. The sequence AAT08029.1 differs from that shown. Reason: Erroneous initiation. Translation N-terminally shortened.The sequence AAT08029.1 differs from that shown. Reason: Frameshift at position 4. The sequence BAD92297.1 differs from that shown. Reason: Erroneous initiation. The sequence CAA48671.1 differs from that shown. Reason: Erroneous initiation.