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Showing papers on "Lanosterol synthase published in 2002"


Journal ArticleDOI
TL;DR: Direct evolution was used to find cycloartenol synthase residues that affect cyclopropyl ring formation, selecting randomly generated cycloarternal synthase mutants for their ability to genetically complement a yeast strain lacking lanosterol synth enzyme.

67 citations


Journal ArticleDOI
TL;DR: To identify mutants that deprotonate differently, randomly generated mutant cycloartenol synthases were selected in a yeast lanosterol synthase mutant and two novel mutants were uncovered.

44 citations


Journal ArticleDOI
01 Dec 2002-Lipids
TL;DR: Computer analysis supports the hypothesis of the structural difference since OSC from S. cerevisiae, A. thaliana, and T. carinii differ in some structural features critical for the interaction with the surface of lipid particles.
Abstract: Cycloartenol synthase from Arabidopsis thaliana and lanosterol synthase from Trypanosoma cruzi and Pneumocystis carinii were expressed in yeast, and their subcellular distribution in the expressing cells was compared. Determination of enzymatic (oxidosqualene cyclase, OSC) activity and SDS-PAGE analysis of subcellular fractions proved that enzymes from T. cruzi and A. thaliana have high affinity for lipid particles, a subcellular compartment rich in triacylglycerols, and steryl esters, harboring several enzymes of lipid metabolism. In lipid particles of strains expressing the P. carinii enzyme, neither OSC activity nor the electrophoretic band at the appropriate M.W. were detected. Microsomes from the three expressing strains retained some OSC activity. Affinity of enzymes from A. thaliana and T. cruzi for lipid particles is similar to that of OSC of Saccharomyces cerevisiae, which is mainly located in this compartment. A different distribution of OSC in yeast cells suggests that they differ in some structural features critical for the interaction with the surface of lipid particles. Computer analysis supports the hypothesis of the structural difference since OSC from S. cerevisiae, A. thaliana, and T. cruzi lack or contain only one transmembrane spanning domain (a structural feature that makes a protein poorly inclined to associate with lipid particles), whereas OSC from P. carinii possesses six transmembrane domains. In the strain expressing cycloartenol synthase from A. thaliana, the accumulation of lipid particles largely exceeded that of the other strains.

37 citations


Journal ArticleDOI
TL;DR: The cyclization of squalene epoxide to lanosterol with baker's yeast with baker’s yeast (Saccharomyces cerevisiae) can conveniently be carried out in aqueous solution with glass cored immobilisates of cells in calcium alginate, enabling the manifold use of the microorganism to obtain Lanosterol in a single biocatalytic step using the immobilisate repeatedly.

7 citations