A MINIMIZED HAMMERHEAD RIBOZYME WITH ACTIVITY AGAINST INTERLEUKIN-2 IN HUMAN-CELLS

A ''minizyme'' is a smaller version of the hammerhead ribozyme, in whi ch stem-loop II has been replaced by a short Linker. Here, we have syn thesised a DNA-containing minizyme and a ribozyme, which are designed to cut within a 15-nucleotide sequence in human interleukin-2 mRNA, an d have tested for their activity in vitro and in cells. In vitro at 37 degrees C, a minizyme with linker of sequence d(GTTTT) cleaves a 15-r ibonucleotide synthetic substrate 8-fold slower than does the full-siz ed ribozyme. In human cells, the minizyme inhibits the production of i nterleukin-2 protein to a similar extent as does the ribozyme. Also, t he minizyme and the ribozyme are more effective in cells than any of t hree controls: an inactive minizyme, a 15-nucleotide antisense DNA, or DNA of random sequence. The positive effect observed in cells indicat es that minizymes may be useful as pharmaceuticals. (C) 1997 Academic Press.