FIGURE 1.

Schematic of the crystal structure of the N-terminal domain of human apoE4, indicating the location of the L28P mutation and SDS-PAGE and MALDI-TOF analyses of purified WT apoE4 and mutant apoE4[L28P]. A and B, the position of the mutated leucine residue on the N-terminal helical segment of apoE4 was mapped on the crystal structure of apoE4 with PDB code 1GS9. C, SDS-PAGE analysis of refolded WT and mutant apoE4, which were produced and purified as described under “Experimental Procedures.” D and E, MALDI-TOF spectra of refolded WT and mutant apoE4. a.u., arbitrary units.