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Updated: Mar 6, 2026

A New Approach for the Comparative Analysis of Multiprotein Complexes Based on 15N Metabolic Labeling and Quantitative Mass Spectrometry
Published on: March 13, 2014
Stereochemical investigations of the Tetrahymena cyclase, a model system for euphane/tirucallane biosynthesis
1Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, NY 13210, USA. jlginer@syr.edu.
Abstract:
The squalene cyclase of Tetrahymena pyriformis cyclizes 2,3-dihydrosqualene to euph-7-ene. This was used as a model for euphane biosynthesis. D-ring formation was demonstrated to involve pre-chair folding through an experiment with 2,3-dihydro-5-oxasqualene. This requires that a non-least motion rotation (120°) of the C17-20 bond in the intermediate deoxydammaranyl cation occurs before the first 1,2-hydride shift. Truncated substrates relieved the hindrance associated with this rotation and permitted a least motion pathway. Several triterpenes were found to be minor products of the Tetrahymena cyclase.
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