ApoE (E7X2A) Rabbit mAb #49285

Apolipoproteins are plasma lipoproteins that function as transporters of lipids and cholesterol in the circulatory system. Chylomicrons are a fundamental class of apolipoproteins containing very low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL) (1,2).
Human ApoE has three isoforms: ApoE2, ApoE3, and ApoE4. These three isoforms differ in the combination of cysteine and arginine residues located at positions 130 and 176. The ApoE4 isoform contains arginine at both locations (3). Arginine 130 in ApoE4 allows for interaction between carboxy- and amino-terminal domains through orientation of arginine 61, leading to a preference for binding lower density lipoproteins, where ApoE2 and ApoE3 show preference for binding HDL. Mouse ApoE contains similar sequence to human ApoE4, with arginine present at equivalent positions to 130 and 176. However, the mouse sequence lacks arginine at critical position 61, which allows it to behave similarly to human ApoE3, including preferential binding to HDL (4).