Functional Characterization of Two Lycopene Cyclases from Sweet Osmanthus (Osmanthus fragrans)

Functional Characterization of Lycopene β- and ε-Cyclases from a Lutein-Enriched Green Microalga Chlorella sorokiniana FZU60

“…Although ε-carotene was produced in the ECOE, it was not detected in C. sorokiniana FZU60 (Figure S3). Similar results were found for the LCYEs from some plants, such as L. sativa [17], O. sativa [18], and O. fragrans [19], with ε-carotenoid being detected in a pigment complementation assay in E. coli but not in its native plants. These results could be due to the difference between the cytoplasmic environment of E. coli and the plastid environments of plants in terms of cofactors, membrane systems, and protein folding mechanisms, etc.…”

“…For example, the LCYEs of H. pluvialis [8] and Chromochloris zofingiensis [16] only exhibit ε-monocyclase activity and can solely catalyze the conversion of lycopene into δ-carotene. However, the LCYEs from Lactuca sativa [17], Oryza sativa [18], and Osmanthus fragrans [19] possess ε-bicyclase activity and can convert lycopene into ε-carotene. Additionally, LCYEs from some species also possess the β-monocyclase activity required to cyclize lycopene into γ-carotene in Escherichia coli, such as CrtLe from Proch.…”

GhLCYε-3 characterized as a lycopene cyclase gene responding to drought stress in cotton

“…Subsequent experiments confirmed that the amino acid sequences of lycopene cyclase of plants and cyanobacteria are highly similar, and they are both composed of 400 amino acid residues and a polypeptide with a molecular weight of 43kD [10] . LCYs have been demonstrated in various plants, classified into two subfamilies, lycopene ε-cyclase and lycopene β-cyclase [11] . In 1996, the function of β and ε lycopene cyclases was analyzed, revealing that it has the function of regulating the proportion of downstream carotenoids produced [12] .…”