Where can I find the protein concentration?

The protein concentration of each product is listed on the Certificate of Analysis. This value is determined for each individual lot and reflects the actual concentration (mg/mL) of the material you received.

Where can I find the recommended storage conditions?

Storage conditions are listed on both the product datasheet and the Certificate of Analysis. These recommendations are based on internal stability assessments and are intended to maintain protein integrity and activity.

Where can I find reconstitution instructions for lyophilized products?

If your product is supplied lyophilized, recommended reconstitution instructions are provided on the product datasheet. These instructions outline the suggested solvent and handling tips to ensure optimal recovery and stability.

How should I store my product after reconstitution?

Unless otherwise stated on the datasheet or COA, we recommend aliquoting reconstituted material and storing at –80 °C to avoid repeated freeze–thaw cycles, which may impact protein stability and activity.

Retinol Binding Protein

Name: Retinol Binding Protein
SKU: 16-16-180216-100UG
Availability: InStock

RBP4

The primary plasma transporter of vitamin A. It binds retinol and then complexes with prealbumin to ensure vitamin A delivery to peripheral tissues.

Purity: ≥95% (SDS-PAGE)

Source: Human Plasma

Molecular Weight: 21 kDa

Form: Lyophilized

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Product Description

Role of protein in biology

Retinol binding protein 4 (RBP4) is a member of the lipocalin family and serves as the primary transporter of retinol (vitamin A) in the bloodstream, present at about 40 mg/L in healthy individuals. Synthesized mainly in the liver, RBP4 binds retinol and forms a complex with transthyretin, which prevents its loss via kidney filtration and ensures efficient delivery of vitamin A to peripheral tissues. Beyond its canonical role in retinoid homeostasis, RBP4 functions as an adipokine and has been implicated in metabolic regulation.

Common research uses

Elevated RBP4 levels are strongly associated with insulin resistance, obesity, type 2 diabetes, gestational diabetes, metabolic syndrome, and cardiovascular diseases, correlating with increased levels of APO B-containing lipoproteins such as LDL and VLDL. RBP4 can also trigger adipose tissue inflammation, linking it to chronic metabolic and inflammatory conditions. Clinically, RBP4 is under investigation as a biomarker for metabolic disorders and chronic kidney disease, and as a potential therapeutic target in diabetes and cardiovascular risk management.

Common uses include IVD Assay standards, calibrators and control, metabolic studies, cardiovascular research.