... targeting (PEST, 1–20) sequenceswere encoded in frame at the C-terminus of scFv. The location of the cysteine mutations into alanine (A) in the variable regions of 2C2A, a site-directed mutant of ... key enzyme in the biosynthesis of polyamines,whose interaction with antizyme, an ODC inhibitoryprotein, confers to the enzyme a half-life of about 1 h.The C-terminal end of ODC contains a PEST ... improving specific imaging andeffective targeting of intracellular antigens by means of intrabodies.ResultsExpression of destabilized scFvs in COS-1 cellsThe functional characteristics of the...