tokens: Analysis of stable Chinese hamster ovary transfectants expressing allele - specific recombinant forms of GPIa showed that anti - Sit ( a ) exclusively reacted with the Glu ( 505 ) Met ( 799 ) , but not with the Glu ( 505 ) Thr ( 799 ) and the Lys ( 505 ) Thr ( 799 ) isoforms .