Moth desaturase characterized that produces both Z and E isomers of Δ11-tetradecenoic acids

The redbanded leafroller moth, Argyrotaenia velutinana (Lepidoptera: Tortricidae) uses a 92:8 mixture of (Z)-11- and (E)-11-tetradecenyl acetate in its pheromone blend. These are produced in the abdominal pheromone gland from the corresponding acids, which are biosynthesized in the gland in a 3:2 Z/E ratio by desaturation of myristoyl CoA. The Delta11 desaturase involved in this reaction exhibits unusual substrate and stereospecificities in specifically producing Z11 and E11 isomers of tetradecenoic acids and exhibiting no activity with C16 and C18 precursor acids. This report describes the cloning and expression of the redbanded leafroller moth Delta11 desaturase, and compares its amino-acid sequence to those of other known insect Z9, Z10, Z11, and E11 desaturases. The metabolic Z9 desaturase from fat body tissue also was cloned and expressed, and found mainly to produce Z9-16:Acid and Z9-18:Acid. The open reading frame of the All desaturase encodes a protein with 329 amino acids, whereas the open reading frame of the Z9 desaturase encodes a protein with 351 amino acids. Addition of this new A I I desaturase with its different substrate and regiospecificifies to the databank of characterized integral-membrane desaturases will be key in efforts to determine amino-acid mutations responsible for the wide array of unsaturated fatty-acid products. (C) 2002 Elsevier Science Ltd. All rights reserved.