AMBP - Alpha-1-Microglobulin-Bikunin Precursor (AMBP) | Elisa - Clia - Antibody - Protein

Background:

α-1-Microglobulin (A1M) and bikunin are two plasma glycoproteins encoded by an α-1-microglobulin/bikunin precursor (AMBP) gene. Despite their lack of any structural or functional relationship, both A1M and bikunin are originate from AMBP cleavage by a furin-like protease that releases the two mature molecules. A1M is present in the plasma, urine, and cerebrospinal fluid. The protein functions to degrade heme and remove free radicals, thereby protecting cells from oxidative stress. Alpha 1 microglobulin (A1M) is a highly glycosylated protein of 27KDa with a heterogenous charge which forms complexes with IgA and albumin. Raised levels of A1M in urine are a good indicator of renal tubular dysfunction.

Protein Structure:

• Composition: The a1M-bikunin precursor is initially synthesized as a single polypeptide chain that is subsequently cleaved to produce a1M and bikunin.
• Domains:
• a1M Domain: Contains the functional sites for binding small molecules and radicals.
• Bikunin Domain: Possesses protease inhibitor properties.

Classification and Subtypes:

• Family: a1M belongs to the lipocalin protein family, characterized by their ability to bind small hydrophobic molecules.
• Subtypes: There are no known subtypes of a1M, but it is associated with its precursor, which also includes bikunin.

Function and Biological Significance:

• Radical Scavenger: a1M is known for its ability to scavenge free radicals, protecting cells and tissues from oxidative stress.
• Heme-Binding Protein: It binds and degrades heme, a potent pro-oxidant, thus preventing heme-induced oxidative damage.
• Immune Modulation: a1M has immunomodulatory properties, influencing inflammation and immune responses.
• Tissue Protection: It protects tissues from damage caused by oxidative stress and inflammation, contributing to its role in various pathological conditions.

Interactions:

• Protease Inhibition: The bikunin part of the precursor inhibits a range of serine proteases, including trypsin, plasmin, and elastase.
• Binding to Hemoglobin and Heme: a1M binds to hemoglobin and heme, facilitating their clearance and reducing oxidative damage.
• Immune Cells: a1M interacts with immune cells, modulating their responses during inflammation and tissue injury.

Clinical Issues:

• Kidney Disease: Elevated levels of a1M are associated with kidney disease, particularly in conditions involving proteinuria and renal inflammation.
• Liver Disease: Changes in a1M levels can be indicative of liver dysfunction, given its primary synthesis in the liver.
• Oxidative Stress: a1M levels can serve as a biomarker for oxidative stress-related conditions and diseases.
• Inflammatory Diseases: Due to its role in immune modulation, a1M is involved in various inflammatory diseases and could potentially be targeted for therapeutic interventions.

Summary:

Alpha-1-microglobulin (a1M) is a multifunctional protein derived from the alpha-1-microglobulin-bikunin precursor. It is involved in scavenging free radicals, binding and degrading heme, and modulating immune responses. The precursor also produces bikunin, a protease inhibitor. a1M's protective roles in oxidative stress and tissue damage make it significant in various pathological conditions, including kidney and liver diseases. It interacts with a range of molecules and cells, highlighting its importance in maintaining cellular and tissue homeostasis. Understanding a1M's functions and clinical implications offers potential for developing diagnostic and therapeutic strategies for related diseases.