Localization of CD45 substrates. (A) Lipid raft isolation shown using GM1 as a marker. Fractions 3 to 6 were pooled and termed raft fractions and fractions 7 to 10 pooled and termed nonraft fractions. Equal proteins loaded for Western blotting. (B) Western blot data for Lck were quantified and ratio of raft to nonraft measured. Pooled data from 3 separate experiments are represented. Significant changes in amounts of Lck moving into rafts seen compared with untreated samples using a heteroscedastic the Student t test. Western blots showing amounts of p56Lck, p59Fyn, and Cbp/PAG after 20-minute stimulations and 60-minute stimulations are also shown. (C) Calcium flux measurements in the presence and absence of anti-CD45RB for 3 donors.