Ribozyme Pharmaceuticals Inc., which is working with Chiron Corp.on drugs to stop production of disease-causing proteins, expanded thealliance to use its ribozyme technology to identify _ from unknownDNA sequences _ genes that may be linked to disorders.

Boulder, Colo.-based Ribozyme's technology involves control ofgene expression through use of ribozymes, which are RNA moleculesthat act as enzymes. The ribozymes are synthesized to target specificmessenger RNA molecules, cleave them and prevent them fromproducing their disease-causing proteins.

The initial Chiron collaboration, negotiated in 1994, focuses on HIV,diabetic retinopathy, corneal transplant rejection, tumor angiogenesisand oncogenes. Ribozyme, which went public in April 1996, andChiron, of Emeryville, Calif., expect to seek approval from the FDAby the end of this year to begin clinical trials of ribozymes targetingHIV.

In the new collaboration, Ralph Christoffersen, Ribozyme's presidentand CEO, said Chiron will provide his company with a list ofunidentified gene sequences and Ribozyme will use its technology todetermine their functions.

"They will give us gene sequences implicated in a disease and wewill determine which one is the most important," Christoffersen said.

Using ribozymes to analyze gene function, he added, is one way tomake use of the huge number of unknown DNA sequences beinggenerated by genomics researchers.

Financial details of Ribozyme's collaborations with Chiron were notdisclosed.

Ribozyme's stock (NASDAQ:RZYM) closed Thursday at $17.25, up50 cents. Chiron (NASDAQ:CHIR), which is Ribozyme's largestshareholder, ended the day $2 higher at $103.50. n

-- Charles Craig

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