4bif

Publication Abstract from PubMed

Hydroxynitrile lyases (HNLs), which catalyse the decomposition of cyanohydrins, are found mainly in plants. In vitro they are able to catalyse the synthesis of enantiopure cyanohydrins, which are versatile building blocks in chemical industry. Recently, HNLs have also been discovered in bacteria. Here, we report on the detailed biochemical and structural characterisation of a hydroxynitrile lyase from Granulicella tundricola (GtHNL), which was successfully heterologously expressed in E. coli. The crystal structure was solved at a crystallographic resolution of 2.5 A and exhibits a cupin fold. As GtHNL does not show any sequence or structural similarity to any other HNL nor contains conserved motifs typical for HNLs, cupins represent a new class of HNLs. GtHNL is metal-dependent as confirmed by ICP-OES and in the structure manganese is bound to three histidine and one glutamine residue. GtHNL displayed a specific activity of 1.74 U mg-1 at pH 6 with (R)-mandelonitrile, and synthesised (R)-mandelonitrile with 90% ee, at 80% conversion of 0.5 M benzaldehyde in a biphasic reaction system with MTBE. This article is protected by copyright. All rights reserved.

Biochemical and structural characterisation of a novel bacterial manganese-dependent hydroxynitrile lyase.,Hajnal I, Lyskowski A, Hanefeld U, Gruber K, Schwab H, Steiner K FEBS J. 2013 Aug 25. doi: 10.1111/febs.12501. PMID:23981508^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.