FUNCTIONAL REGIONS OF ORNITHINE DECARBOXYLASE ANTIZYME

Degradation of ornithine decarboxylase, a key enzyme in polyamine bios ynthesis, is accelerated by the binding of antizyme, an ornithine deca rboxylase inhibitory protein induced by polyamines. In the present stu dy, we examined the effects of a series of deletion mutants of rat ant izyme. The results indicated that two regions of antizyme, one interna l (amino acids 122-144) and the other near the C-terminus (amino acids 211-218) are necessary for its binding to ornithine decarboxylase and inhibition of its activity, and an additional internal region (amino acids 88-118, especially 113-118) is necessary for its destabilization . (C) 1994 Academic Press, Inc.