RBP4 Protein, Human, Recombinant (His Tag)

Product Specifications

Background

Retinol-binding protein 4 (RBP4) is the specific carrier for retinol (also known as vitamin A), and is responsible for the conversion of unstable and insoluble retinol in aqueous solution into stable and soluble complex in plasma through their tight interaction. As a member of the lipocalin superfamily, RBP4 containing a β-barrel structure with a well-defined cavity is secreted from the liver, and in turn delivers retinol from the liver stores to the peripheral tissues. In plasma, the RBP4-retinol complex interacts with transthyretin (TTR), and this binding is crucial for preventing RBP4 excretion through the kidney glomeruli. RBP4 expressed from an ectopic source efficiently delivers retinol to the eyes, and its deficiency affects night vision largely. Recently, RBP4 as an adipokine, is found to be expressed in adipose tissue and correlated with obesity, insulin resistance (IR) and type 2 diabetes (T2DM) .

Overview

A DNA sequence encoding the pro form of human RBP4 (NP_006735.2) (Met 1-Leu 201) was expressed with a C-terminal polyhistidine tag.

Synonyms

RDCCAS Protein, Human

Gene Name

Retinol binding protein 4, plasma

Expression System

HEK293 Cells

Tag

C-His

Endotoxin

< 1.0 EU per μg of the protein as determined by the LAL method.

Purity

> 85 % as determined by SDS-PAGE.

Activity

Measured by its ability to bind all-trans retinoic acid. The binding of retinoic acid results in the quenching of Trp fluorescence in RBP4.The 50% binding concentration (BC50) is > 1.0 μM.

Form

Lyophilized

Buffer

Lyophilized from sterile PBS, pH 7.2 Please contact us for any concerns or special requirements. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween 80 are added as protectants before lyophilization. Please refer to the specific buffer information in the hard copy of CoA.

Molecular Weight

The recombinant human RBP4 consists of 194 amino acids after removal of the signal peptide and migrates as an approximately 23 kDa protein as predicted.

Storage Conditions

In general, recombinant proteins are provided as lyophilized powder which are shipped at ambient temperature. Bulk packages of recombinant proteins are provided as frozen liquid. They are shipped out with blue ice unless customers require otherwise. Stable for 1 year at -20°C or below from date of shipment. For maximum recovery of product, centrifuge the original vial after thawing and opening the cap. For long-term storage, aliquot and store at -20°C or below. Avoid repeated freeze-thaw cycles.