RBP Human, Native
Urine from the patients with renal tubular proteinuria.
Sterile Filtered White lyophilized (freeze-dried) powder.
Greater than 96.0%.
Description
Human Retinol Binding Protein Native produced in urine from the patients with renal tubular proteinuria having a molecular mass of approximately 21kD.
Product Specs
Human Retinol Binding Protein (RBP) is a protein responsible for binding and transporting vitamin A throughout the body. It forms a complex with prealbumin in the bloodstream to prevent excessive filtration by the kidneys. Only the retinol-free form of RBP, lacking affinity for prealbumin, undergoes glomerular filtration due to its small size. This form is then reabsorbed and broken down by tubular cells in the kidneys.
This product consists of naturally-produced Human Retinol Binding Protein, isolated from the urine of patients with renal tubular proteinuria. Its molecular weight is approximately 21 kDa.
Sterile, white powder, freeze-dried and filtered.
The protein was lyophilized after passing through a 0.2 µm filter, from a solution containing 20mM ammonium bicarbonate (NH₄HCO₃).
For reconstitution, it is recommended to dissolve the lyophilized Human RBP in a phosphate buffer containing 0.15M NaCl.
Human RBP remains stable at room temperature for up to 3 weeks. However, for long-term storage, it is recommended to store the product between 2-8°C.
The purity of this product is greater than 96%.
The donor of the starting material for this product has tested negative for antibodies against HIV-1, HIV-2, Hepatitis C Virus (HCV), Hepatitis B surface antigen (HBSAg), and Syphilis.
Urine from the patients with renal tubular proteinuria.
Product Science Overview
RBP4 is synthesized primarily in the liver, where it binds to retinol to form a complex. This complex then associates with another protein called transthyretin (TTR), which prevents the renal filtration of RBP4, thereby maintaining its presence in the bloodstream . The retinol-RBP4-TTR complex circulates in the blood and delivers retinol to target tissues by binding to specific membrane receptors .
Vitamin A is essential for numerous physiological functions, including vision, immune response, reproduction, embryonic development, and cell proliferation and differentiation . The active metabolite of vitamin A, all-trans retinoic acid (atRA), acts as a high-affinity ligand for retinoic acid receptors (RARs), which are nuclear receptors that regulate gene expression . Additionally, 11-cis retinaldehyde, another derivative of vitamin A, is crucial for the visual cycle in the retina .
RBP4 was first identified in 1968 by Kanai et al., who described it as a human plasma protein specifically bound to retinol . Since then, extensive research has been conducted to understand its structure, regulation, and functions. Recent studies have also highlighted the non-canonical functions of RBP4, which are independent of retinol transport .
Mutations or defects in RBP4 can lead to various health conditions due to dysregulated retinoid homeostasis. These conditions can affect embryonic development, vision, metabolism, and cardiovascular health . Understanding the role of RBP4 in these processes is crucial for developing therapeutic strategies for related diseases.
