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Actions of Tryptophan Prenyltransferases Toward Fumiquinazolines and their Potential Application for the Generation of Prenylated Derivatives by Combining Chemical and Chemoenzymatic Syntheses
Author(s) -
Mai Peter,
Zocher Georg,
Ludwig Lena,
Stehle Thilo,
Li ShuMing
Publication year - 2016
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201600064
Subject(s) - prenylation , chemistry , indole test , stereochemistry , tryptophan , moiety , streptomyces , enzyme , biochemistry , amino acid , biology , bacteria , genetics
D i m ethyl a llyl t ryptophan s ynthases (DMATSs) catalyze regiospecific transfer reactions of a prenyl moiety from dimethylallyl diphosphate to various positions of the indole ring of tryptophan. For example, FgaPT2, 5‐DMATS, and 7‐DMATS from Aspergillus fungi catalyze tryptophan prenylation at C‐4, C‐5, and C‐7, while 5‐DMATS Sc and 6‐DMATS Sa from Streptomyces strains are tryptophan C‐5 and C‐6 prenyltransferases, respectively. In this study, our objective is to demonstrate the possibility of producing prenylated analogues of ardeemin fumiquinazoline (FQ) ( 1a ), a precursor of the m ulti d rug r esistance (MDR) export pump inhibitor ardeemin, by using DMATSs. All ardeemin FQ stereoisomers were chemically synthesized and used as substrates for enzyme assays with DMATSs. Biochemical investigations revealed different features of these enzymes toward ardeemin FQ analogues, regarding activity and prenylation position. Isolation and structural elucidation showed that 7‐DMATS catalyzed mainly regiospecific prenylation at C‐7, which is also observed for its natural substrate L ‐tryptophan. Up to four prenylated derivatives were identified in the reaction mixtures of other enzymes. In total, 18 new prenylated ardeemin FQ analogues were obtained in this study. Molecular modelling of ardeemin FQ analogues with the crystal structure of FgaPT2 led to the identification of two potential amino acid residues for guidance of the prenylation position. The two generated mutants FgaPT2_M328L and FgaPT2_Y398F showed significant prenylation shifts with 1a .