APOM - Apolipoprotein M | Elisa - Clia - Antibody - Protein

Background:

Apolipoprotein M (APOM) is a protein associated with lipoproteins, specifically high-density lipoprotein (HDL), in the bloodstream. APOM is encoded by the APOM gene located on chromosome 6 in humans. It consists of two exons and one intron and spans approximately 6 kilobases.APOM is primarily expressed in the liver and kidney, with lower levels of expression in other tissues such as the intestines and adipose tissue. APOM is primarily associated with HDL, a type of lipoprotein known for its role in transporting cholesterol from peripheral tissues to the liver for excretion. APOM is mainly found bound to HDL particles in the bloodstream.Biological Function: The exact biological function of APOM is not fully understood, but research suggests it may play a role in lipid metabolism and transport. APOM has been proposed to modulate the metabolism and anti-inflammatory properties of HDL, potentially influencing processes such as cholesterol efflux, endothelial function, and inflammation. Disease Associations: Studies have suggested that APOM may be involved in various pathological conditions, including atherosclerosis, diabetes, and inflammation. Altered levels of APOM have been observed in individuals with these conditions, although the precise role of APOM in disease pathogenesis remains to be fully elucidated.

Protein Structure:

• Primary Structure: APOM is a small protein consisting of approximately 188 amino acids.
• Secondary Structure: The protein features a typical apolipoprotein fold, including alpha helices that are essential for its function in lipid binding.
• Tertiary Structure: APOM has a lipocalin-like structure, which forms a beta-barrel that can bind to small hydrophobic molecules, such as lipids.
• Quaternary Structure: It exists as a monomer in plasma and can form complexes with HDL particles.

Classification and Subtypes:

APOM is classified as a member of the lipocalin protein family, known for their ability to transport small hydrophobic molecules. It does not have distinct subtypes but varies in its association with different lipoprotein particles (HDL, LDL, VLDL).

Function and Biological Significance:

APOM has several important functions in the body:

• Lipid Transport: APOM plays a critical role in the transport and metabolism of lipids. It is involved in the transfer of sphingosine-1-phosphate (S1P), a signaling molecule crucial for vascular and immune system functions.
• Antioxidant Properties: It has antioxidant properties that help protect lipids from oxidative damage, contributing to the anti-atherogenic effects of HDL.
• Endothelial Function: APOM and its associated S1P are essential for maintaining endothelial barrier function and vascular integrity.
• Immune Modulation: APOM influences immune responses by regulating the bioavailability of S1P, which has immunomodulatory effects.

Interactions:

APOM interacts primarily with HDL particles, where it helps stabilize and transport various lipid molecules. Its interaction with S1P is particularly significant for its role in vascular biology and immune responses.

Clinical Issues:

• Cardiovascular Diseases: Altered levels of APOM are associated with cardiovascular diseases. Lower levels of APOM are linked to increased risk of atherosclerosis and other cardiovascular conditions due to reduced antioxidant and anti-inflammatory protection.
• Metabolic Disorders: Changes in APOM levels are also observed in metabolic syndromes, including diabetes and obesity. Its role in lipid metabolism makes it a potential marker for these conditions.
• Therapeutic Potential: Targeting APOM levels or its interaction with S1P might offer new therapeutic strategies for treating cardiovascular and metabolic diseases.

Summary:

Apolipoprotein M (APOM) is a key player in lipid metabolism, primarily associated with HDL particles. It has significant roles in transporting lipids, providing antioxidant protection, and maintaining vascular integrity. Its interactions with lipoproteins and S1P make it crucial for cardiovascular and immune system health. Altered APOM levels are linked to various diseases, highlighting its potential as a biomarker and therapeutic target in cardiovascular and metabolic disorders. Further research is needed to fully understand its mechanisms and therapeutic applications.