Enzymatic desaturation of stearyl acyl carrier protein.

Stearyl acyl carrier protein, chemically prepared from 1-W stearic acid and Escherichia co2i acyl carrier protein, is desaturated to oleic acid by extracts of photoauxotrophic Euglena gracilis and of spinach. The soluble stearyl acyl carrier protein desaturase system from Eug~ena has been separated into three components, a reduced triphosphopyridine nucleotide oxidase, the desaturase, and a nonheme iron protein (ferredoxin). The enzyme requires reduced triphosphopyridine nucleotide and molecular oxygen. Desaturation is inhibited by KCN but is not affected by carbon monoxide.