Recombinant Human Apolipoprotein E4/ApoE4 Protein, CF

Measured by its binding ability in a functional ELISA. Recombinant Human Apolipoprotein E4/ApoE4 Protein (Catalog # 11736-AE) binds to Recombinant Human VLDLR Protein (8444-VL) with an ED50 of 10.0‑100 ng/mL.

2 μg/lane of Recombinant Human Apolipoprotein E4/ApoE4 Protein (Catalog # 11736-AE) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 32-39 kDa, under reducing conditions.

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human Apolipoprotein E4/ApoE4 Protein, CF Summary

• Additional Information: HEK Expressed
• Details of Functionality: Measured by its binding ability in a functional ELISA. Recombinant Human Apolipoprotein E4/ApoE4 binds to Recombinant Human VLDLR Protein (Catalog # 8444-VL) with an ED₅₀ of 10.0‑100 ng/mL.
• Source: Human embryonic kidney cell, HEK293-derived human Apolipoprotein E4/ApoE4 protein
  Lys19-His318
• Accession #: AAB59397.1
• N-terminal Sequence: Lys 19
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 34 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 32-39 kDa, under reducing conditions.

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in MOPS, NaCl and TCEP with Trehalose.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining
• Reconstitution Instructions: Reconstitute at 250 μg/mL in water.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human Apolipoprotein E4/ApoE4 Protein, CF

• LDLCQ5
• Apo-E
• apolipoprotein E
• apolipoprotein E3
• Apolipoprotein E4/ApoE4
• late onset)
• MGC1571

Background

Apolipoprotein E (ApoE) is a polymorphic lipid-transport protein with three major human isoforms-ApoE2, ApoE3, and ApoE4-differing by single amino acid substitutions at residues 112 and 158, which significantly alter their structure and function [1, 2]. All isoforms share a two-domain structure: the N-terminal domain mediates receptor binding, while the C-terminal domain facilitates lipid binding and oligomerization [2]. ApoE3 (Cys112/Arg158) is the most common and functionally neutral isoform, while ApoE2 (Cys112/Cys158) has reduced affinity for LDL receptors, often leading to type III hyperlipoproteinemia in homozygotes [1, 4]. ApoE4 (Arg112/Arg158) exhibits a more compact and less stable structure due to domain interaction, predisposing it to pathological effects in the brain [2, 5]. Functionally, ApoE isoforms differentially regulate neuronal metabolism: ApoE2 enhances glycolytic activity and hexokinase expression, promoting neuroprotection, whereas ApoE4 impairs these pathways, increasing vulnerability to aging and Alzheimer's disease (AD) [1]. Recent transcriptomic and epigenomic profiling of human microglia in an AD xenotransplantation model revealed that ApoE isoforms distinctly shape gene expression and chromatin accessibility. ApoE4 drives pro-inflammatory and neurodegenerative signatures, while ApoE2 supports homeostatic microglial states [3]. Clinically, ApoE genotyping is widely used to assess AD risk, with ApoE4 being the strongest genetic risk factor and ApoE2 offering relative protection [4, 5]. Therapeutic strategies targeting ApoE include isoform-specific modulation and gene editing. Additionally, ApoE isoforms are valuable tools in translational research for drug screening, biomarker discovery, and personalized medicine [4].

1. Zhang X, et al. (2023)  Cells 12:410.
2. Horn JVC, et al. (2023) Mol Cell Biochem 478: 173.
3. Murphy KB, et al. (2025) Nat Commun 16:4883.
4. Mahley RW, et al. (2012) J Lipid Res 53:539.
5. Liu CC, et al. (2013) Nat Rev Neurol 9:106.

Bioinformatics

• Uniprot:
  • AAB59397.1()