Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by DEPASS, L. R.
Right arrow Articles by HEYMAN, I. A.
Right arrow Search for Related Content
PubMed
Right arrow Articles by DEPASS, L. R.
Right arrow Articles by HEYMAN, I. A.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 1991 Oxford University Press

research-article

False Positive Result for a Peptide Drug in the Gene Conversion Assay with Saccharomyces cerevisiae Strain D71

LINVAL R. DEPASS*, REBECCA L. CHAN*, D. R. JAGANNATH{dagger} and IRWIN A. HEYMAN*

*Syntex Research Palo Alto, Cal fornia 94304 {dagger}Hazleton Biotechnologies Kensington, Maryland 20895

Received February 12, 1991; accepted May 29, 1991

False Positive Result for a Peptide Drug in the Gene Conversion Assay with Saccharomyces cerevisiae Strain D7. DEPASS, L. R., CHAN, R. L., JAGANNATH, D. R., AND HEYMAN, I. A. (1991). Fundam. Appl Toxicol. 17, 627–634. A battery of mutagenicity tests was performed with nafarelin, an agonist analogue of luteinizing hormone releasing hormone (LHRH) containing tryptophan (Trp) and histidine (His). Included were the Ames assay and the gene conversion assay with yeast strain D7. Both tests were negative without S9 activation, and the Ames test was negative with S9, but the yeast test was positive with S9 activation. Since the yeast test is based on conversion of cells to Trp independence, release of Trp by metabolism of the drug could account for the positive result The test was repeated using Trp instead of the drug. The result was positive even at the lowest Trp concentration. In another experiment with the drug, amino acid analysis of the incubation mixture revealed the presence of Trp but no detectable His. Since the Ames test is based on mutation to His-independent cells, these data are completely consistent with the negative result in the Ames test and the false positive result in the yeast test. These data suggest the need for caution in interpreting the results from mutagenicity assays with peptide drugs.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.