RBP4 Human, His

Retinol Binding Protein-4 (RBP4) is a member of the lipocalin family and plays a crucial role in the transport of retinol (vitamin A alcohol) in the blood. This protein is essential for delivering retinol from liver stores to peripheral tissues, ensuring proper vitamin A distribution throughout the body .

RBP4 is a small protein with a molecular mass of approximately 21 kDa. The human recombinant version of RBP4, tagged with a His (histidine) tag, is produced using recombinant DNA technology. This His tag facilitates the purification of the protein through affinity chromatography, making it easier to isolate and study .

In the bloodstream, RBP4 forms a complex with retinol and interacts with another protein called transthyretin. This interaction prevents the loss of the RBP4-retinol complex through kidney filtration, ensuring that retinol is efficiently delivered to target tissues .

The recombinant human RBP4 with a His tag is typically produced in E. coli or human embryonic kidney (HEK293) cells. The His tag, usually consisting of six histidine residues, is added to the N- or C-terminus of the protein. This tag allows for easy purification using immobilized metal ion affinity chromatography (IMAC), which exploits the affinity of histidine residues for metal ions like nickel or cobalt .

Recombinant RBP4 is widely used in research to study vitamin A metabolism, retinol transport mechanisms, and related diseases. It is also employed in the development of diagnostic assays and therapeutic interventions for conditions associated with vitamin A deficiency .

Mutations or dysregulation of RBP4 can lead to various health issues, including retinal dystrophy, iris coloboma, and comedogenic acne syndrome. Understanding the function and regulation of RBP4 is crucial for developing treatments for these conditions .