Fig. 1. Fluorescence excitation-emission spectra (A) and gradient gel electrophoresis (B) of native and tyrosylated HDL apolipoproteins. (A) Native and tyrosylated HDL₃ were subjected to fluorescence spectroscopy with ex at 328 nm and em at 300 nm to 500 nm. (B) SDS-PAGE was performed using 5-20% polyacrylamide gradient gels under non-reducing conditions as described in Materials and Methods. Lanes: 1, apo A-I; 2, apoA-II; 3, native HDL₃; 4, tyrosylated HDL₃; 5, native total HDL; 6, tyrosylated total HDL; 7, molecular weight standards.