β-Rutinosidase (L-rhamnosyl-α(1-6)-β-D-glucopyranosidase) is a new diglycosidase [1] that has been so far described as an “activity”, but respective protein was not characterized and its gene (sequence) is not known. Therefore, this enzyme is not included into the CAZY system. This enzyme cleaves rutinose from various (often polyphenolic) substrates, such as rutin (quercetin-3-rutinoside). We have prepared colorimetric substrate e.g., p-nitrophenylb-rutinoside by the enzymatic synthesis from p-nitrophenyl b-D-glucopyranoside using a-L-rhamnosidase from A. terreus (recombinant) [2] and L-rhamnose as the donor. Extensive screening among filamentous fungi yielded extracellular β-rutinosidase from Penicillium oxalicum, Chaetomium globosum, Mucor circinelloides and Aspergillus niger. Sequence of the enzyme fromA. niger was compared with its genome and a high homology was found with the tentative b-1,3-exoglucosidase (GenBank XP_001392228.1). The enzyme is now being cloned and crystallized to obtain 3D structure. β-Rutinosidase fromP. oxalicum has excellent transglycosylation ability transferring b-rutiose from rutin onto various acceptors, such as saturated and unsaturated alcohols (ethanol, butanol, pentanol, benzylalcohol, octanol, linalool) cyclic alcohols (e.g. cyclohexanol), terpenols (e.g. geraniol), branched alcohols (e.g. terc-butyl alcohol), and phenols (catechol, trans-resveratrol) in a good yield. This enzyme is rather unique due to its ability to glycosylate effectively polyphenolic compounds. It has also potential application in vine and food technology.
Literature
1. Mazzaferro L.S., Breccia J.D.:Biocat. Biotrans.29, 1-10 (2011).
2. Weignerová L., Marhol P., Gerstorferová D., Křen V.:Biores. Technol.,115, 222-227 (2012)
Acknowledgement:
This work was supported by theEU projectNOVOSIDES FP7-KBBE-2010-4-265854
