AFM - Afamin | Elisa - Clia - Antibody - Protein

Background

Afamin, also known as alpha-albumin or vitamin E-binding protein, is a member of the albumin protein family. It is primarily produced in the liver and secreted into the bloodstream, where it functions as a carrier protein for vitamin E. Afamin has a high affinity for various forms of vitamin E, including alpha-tocopherol and gamma-tocopherol. Afamin binds to vitamin E molecules, protecting them from degradation and facilitating their transport to cells throughout the body. Vitamin E is an important antioxidant that helps protect cells from damage caused by free radicals. Afamin may also have additional biological functions, such as inflammation, lipid metabolism, and insulin resistance. However, the full scope of its functions is still being investigated. Afamin levels in the blood have been associated with various health conditions. For example, lower levels of afamin have been observed in individuals with metabolic syndrome, diabetes, and cardiovascular disease. Additionally, afamin levels may be influenced by factors such as age, sex, and hormonal status.

Protein Structure

Afamin is a complex glycoprotein with structural features typical of the albumin family:

• N-terminal region: Contains a signal peptide directing the protein to the secretory pathway.
• Central domain: Characterized by multiple alpha-helical regions that facilitate its stability and solubility in plasma.
• C-terminal region: Involved in the binding of vitamin E and other hydrophobic molecules.

Classification and Subtypes

Afamin is a single gene product without known major subtypes. It is classified as a member of the albumin gene family due to its structural similarities and functional properties shared with albumin, alpha-fetoprotein, and vitamin D-binding protein.

Function and Biological Significance

Afamin has several important biological functions:

1. Vitamin E Transport: Afamin binds and transports vitamin E (alpha-tocopherol) in the blood, playing a crucial role in delivering this essential antioxidant to tissues.
2. Antioxidative Protection: By transporting vitamin E, afamin contributes to the protection of cells and tissues from oxidative damage.
3. Reproductive Health: Afamin is found in high concentrations in follicular fluid, indicating a potential role in female fertility and reproductive processes.
4. Metabolic Regulation: Emerging evidence suggests afamin might be involved in metabolic regulation and insulin sensitivity, linking it to conditions such as obesity and type 2 diabetes.

Interactions

1. Vitamin E: Afamin binds alpha-tocopherol, a form of vitamin E, facilitating its transport and distribution throughout the body.
2. Other Albumin Family Members: Although afamin's primary function is distinct, it shares some binding properties with other albumin family proteins, potentially interacting with similar hydrophobic molecules.

Clinical Significance

1. Oxidative Stress and Disease: Given its role in transporting vitamin E, afamin is implicated in diseases associated with oxidative stress, such as cardiovascular diseases and neurodegenerative disorders.
2. Metabolic Disorders: Elevated levels of afamin have been observed in individuals with obesity, insulin resistance, and type 2 diabetes, suggesting it could serve as a biomarker for these conditions.
3. Reproductive Health: Afamin levels in follicular fluid may be indicative of oocyte quality and overall fertility, making it a potential biomarker for reproductive health assessments.
4. Cancer: Research is exploring afamin's potential role in cancer. Afamin is a tumor marker for ovarian cancer and possibly other cancer types.

Summary

Afamin is a multifunctional glycoprotein primarily involved in the transport of vitamin E and contributing to antioxidative protection. It plays roles in reproductive health, metabolic regulation, and potentially in the pathogenesis of various diseases associated with oxidative stress and metabolic disorders. Understanding afamin's functions and interactions offers insights into its significance in health and disease, highlighting its potential as a biomarker for various clinical conditions.