Fig. 2

AGE-specific binding by human fetal astrocytes. (A) ¹²⁵I-AGE-BSA specific binding kinetic analysis on human astrocytes incubated at the indicated ligand concentrations (2 hr, 4°C) in the presence or absence of excess amounts of unalabeled ligand, as described. Data represent the mean ± SD of four independent experiments, each done in triplicate; insert: Scatchard analysis of the binding data. (B) ¹²⁵I-AGE BSA (10 µg) binding specificity by U87 MG cell membrane fractions (2.7 αg) was tested by ligand blot analysis in the presence or absence of excess amount (×100) of unlabeled AGE-BSA, FFI-BSA, native BSA, and Amadori product. (C) Degradation of ¹²⁵I-AGE-BSA by fetal astrocytes is abolished in the presence of unlabeled AGE-BSA; no significant degradation of unmodified carrier BSA was noted. Cell cultures were incubated with the radiolabeled ligands (50 µg/ml each) as shown for 6 or 22 hr at 37°C; data represent the mean of three experiments, each in duplicate.