... Ðkfa2kra2Sa2Á S À!kcata2Sa2þ Sa1ð1Þ The autophosphorylation rate (v3) is the sum of the rates catalyzed by each form. Applying quasi steady-state (QSS) approximation for the intermediate com-plexes, ... and the activatory residue is dephosphorylated; S is the partially active form, where both the inhibitory and activatory resi-dues are dephosphorylated; Sa1 is the fully active conformation,where ... If the negative-regulatorytyrosine residue Yi is phosphorylated, whereas the acti-vatory residue Ya is dephosphorylated, Src is catalyti-cally inactive. In this autoinhibited conformation,...