Biochemical characterization of the $\alpha$-L-Rhamnosidase DtRha from dictyoglomus thermophilum : Application to the selective derhamnosylation of natural flavonoids

Laure Guillotin (1, 2) , Hyuna Kim (1, 2) , Yasmina Traore (1, 2) , Philippe Moreau (1, 2) , Pierre Lafite (1, 2) , Véronique Coquoin (3) , Sylvie Nuccio (3) , René de Vaumas (3) , Richard Daniellou (1, 2)

1 ICOA - Institut de Chimie Organique et Analytique
2 UO - Université d'Orléans
3 Extrasynthese

$\alpha$-l-Rhamnosidases are catalysts of industrial tremendous interest, but their uses are still somewhat limited by their poor thermal stabilities and selectivities. The thermophilic DtRha from Dictyoglomus thermophilum was cloned, and the recombinant protein was easily purified to homogeneity to afford 4.5 mg/L culture of biocatalyst. Michaelis-Menten parameters demonstrated it to be fully specific for $\alpha$-l-rhamnose. Most significantly, DtRha demonstrated to have a stronger preference for $\alpha$(1 → 2) linkage rather than $\alpha$(1 → 6) linkage when removing rhamnosyl moiety from natural flavonoids. This selectivity was fully explained by the difference of binding of the corresponding substrates in the active site of the protein.

Domaines: Biotechnologies; Chimie

Laure Guillotin, Hyuna Kim, Yasmina Traore, Philippe Moreau, Pierre Lafite, et al.. Biochemical characterization of the $\alpha$-L-Rhamnosidase DtRha from dictyoglomus thermophilum : Application to the selective derhamnosylation of natural flavonoids. ACS Omega, 2019, 4 (1), pp.1916-1922. ⟨10.1021/acsomega.8b03186⟩. ⟨hal-03478307⟩