| Identified Mutation |
ARG158CYS; The 3 major isoforms of human apolipoprotein E (apoE2, -E3, and -E4), as identified by isoelectric focusing, are coded for by 3 alleles (epsilon 2, 3, and 4). The E2 (107741.0001), E3 (107741.0015), and E4 (107741.0016) isoforms differ in amino acid sequence at 2 sites, residue 112 (called site A) and residue 158 (called site B). At sites A/B, apoE2, -E3, and -E4 contain cysteine/cysteine, cysteine/arginine, and arginine/arginine, respectively [Weisgraber et al. J. Biol. Chem. 256: 9077-9083 (1981) and Rall et al. Proc. Nat. Acad. Sci. 79: 4696-4700 (1982)]. |