Table 1.
Human APOE polymorphisms and differences by species.
| A: Human APOE polymorphisms and differences by species | |||
| ApoE Residue (mature peptide) | 61 | 112 | 158 |
| ApoE2 | Arginine (R) | Cysteine (C) | C |
| ApoE3 | R | C | R |
| ApoE4 | R | R | R |
| Chimpanzee | Threonine (T) | R | R |
| Mouse | T | R | R |
| B: APOE 2 and 4 alleles: prevalence and major characteristics | |||
| APOE 4 | APOE 2 | ||
| Population Frequency* | 3-41% | 1-38% | |
| R61—Glu255 domain interactions | Present | Absent | |
| Protein aggregation | Increased | Lower | |
| Biochemical Properties | Enhanced binding to lipids | Reduced binding to the LDL-receptor compared with E3 and E4 | |
| Lipid Metabolism | Hypercholesterolemia Hypertriglyceridemia | A small percentage have hypertriglyceridemia | |
| BMI and disease association | Lower BMI, particularly with aging | Greater BMI with homozygotes | |
| Insulin resistance | Increased | Lower | |
| Chronic Inflammation | Enhanced response to inflammation | Lower response to inflammation | |
| Brain amyloid plaque accumulation | Increased | Lower | |
| Alzheimer’s disease risk | Increased | Protective | |
| Blood-brain barrier integrity | Compromised | Not studied | |
| Vascular system | Increased atherosclerosis | Mixed. Protects against heart disease, but increases risk of intracranial hemorrhages | |