Identification and characterization of new Δ-17 fatty acid desaturases

Autor: Hongxian He, Hongxiang Zhang, Bogdan Szostek, Dieter Hollerbach, Daniel Joseph Macool, Zhixiong Xue, Quinn Qun Zhu, Narendra S. Yadav
Rok vydání: 2012
Předmět:
ω-3 Fatty acids
Yarrowia lipolytica
Fatty Acid Desaturases
Models
Molecular
Phytophthora
Long-chain polyunsaturated fatty acids
Molecular Sequence Data
Gene Expression
Yarrowia
Pythium
Saprolegnia
Applied Microbiology and Biotechnology
Substrate Specificity
Metabolic engineering
chemistry.chemical_compound
ω-3 Desaturase
Amino Acid Sequence
Cloning
Molecular
Biotechnologically Relevant Enzymes and Proteins
Δ-17 Desaturase
Biotransformation
chemistry.chemical_classification
Arachidonic Acid
Sequence Homology
Amino Acid
biology
Fatty acid
General Medicine
biology.organism_classification
Eicosapentaenoic acid
Recombinant Proteins
Amino acid
Fatty acid desaturase
Eicosapentaenoic Acid
chemistry
Biochemistry
biology.protein
Arachidonic acid
Sequence Alignment
Biotechnology
Polyunsaturated fatty acid
Zdroj: Applied Microbiology and Biotechnology
ISSN: 1432-0614
0175-7598
DOI: 10.1007/s00253-012-4068-2
Popis: ω-3 fatty acid desaturase is a key enzyme for the biosynthesis of ω-3 polyunsaturated fatty acids via the oxidative desaturase/elongase pathways. Here we report the identification of three ω-3 desaturases from oomycetes, Pythium aphanidermatum, Phytophthora sojae, and Phytophthora ramorum. These new ω-3 desaturases share 55 % identity at the amino acid level with the known Δ-17 desaturase of Saprolegnia diclina, and about 31 % identity with the bifunctional Δ-12/Δ-15 desaturase of Fusarium monoliforme. The three enzymes were expressed in either wild-type or codon optimized form in an engineered arachidonic acid producing strain of Yarrowia lipolytica to study their activity and substrate specificity. All three were able to convert the ω-6 arachidonic acid to the ω-3 eicosapentanoic acid, with a substrate conversion efficiency of 54-65 %. These enzymes have a broad ω-6 fatty acid substrate spectrum, including both C18 and C20 ω-6 fatty acids although they prefer the C20 substrates, and have strong Δ-17 desaturase activity but weaker Δ-15 desaturase activity. Thus, they belong to the Δ-17 desaturase class. Unlike the previously identified bifunctional Δ-12/Δ-15 desaturase from F. monoliforme, they lack Δ-12 desaturase activity. The newly identified Δ-17 desaturases could use fatty acids in both acyl-CoA and phospholipid fraction as substrates. The identification of these Δ-17 desaturases provides a set of powerful new tools for genetic engineering of microbes and plants to produce ω-3 fatty acids, such as eicosapentanoic acid and docosahexanoic acid, at high levels.
Databáze: OpenAIRE
Externí odkaz: