Dactylium dendroides galactose oxidase

Scheme 3 Synthesis of 3-D-GalpNAcA-(l -> 4)-d-G1c/>NAc by coupled use of galactose oxidase from Dactylium dendroides and P-W-acetylhexosaminidase from Talaromyces flavus, followed by in situ chemical oxidation.76...

In early 1990 it became apparent that the structure of galactose oxidase from Dactylium dendroides was about to emerge. A 2.5 A multiple isomor-phous replacement (MIR) map based on area detector data from a native and three derivative crystals yielded a polypeptide chain tracing. The refined structure at 1.9 A (R = 0.179) (Ito et al., 1991) shows that galactose oxidase consists of three domains, each of which is predominandy jS... 

McPherson, M. J., Ogel, Z. B., Stevens, C., Yadav, K. D. S., Keen, J. N., and Knowles, P. F., Galactose oxidase of Dactylium dendroides gene cloning and sequence analysis, 1992, J. Biol. Chem. 267 8146n8152. 

Ogel, Z. B., Brayford, D., and McPherson, M. J., 1994, Cellulose-triggered sporulation in the galactose oxidase producing fungus Cladobotryum (Dactylium) dendroides NRRL-2903 and its reidentification as a species of Fusarium, Mycology Research 98 4748480. 

Scheme 6. Preparation of pentasaccharide 11 [42] (a) galactose oxidase Dactylium dendroides), catalase (bovine liver), phosphate buffer, 37 °C (b) 5-(2-aminoethylamino)-l-naphthalene-sulfonate (EDANS), MeOH, reflux, then NaBHjCN...

Galactose oxidases belong to the group of copper-dependent oxidases. For the GAOX from Dactylium dendroides the existence of covalently bound pyrroloquinoline quinone (PQQ) could be shown[145. It catalyzes the specific oxidation of the hydroxyl group in position 6 of galactose (Fig. 16.2-33)[1501. 

Galactose oxidase (EC 1.1.3.9) differs significantly from the other non-blue oxidases. The enzyme (from the fungus Dactylium dendroides) consists of a single peptide chain of 639 amino acids [152] and has a molecular mass of 68 kD [30]. The active center contains a single type 2 copper center. It has neither additional, dissociable prosthetic groups nor TOPA quinone, the typical cofactor of the other non-blue oxidases [153]. 

The crystal structure of galactose oxidase from the fungus Dactylium dendroides has been determined. Accordingly, galactose oxidase (639 amino acid residues) consists of three domains predominantly formed from /3-structures (Figure 14). The first domain (residues 1-155) has a /3-sandwich structure. The catalytic domain (residues 156-532) comprises a seven-fold /3-propeller based on the kelch structural motif The copper lies on the solvent-accessible surface of this domain close to the pseudo seven-fold axis. The third domain (residues 533-639) is comprised of seven /3-strands. The copper site on the second domain lies in a region extremely rich... 

The D-galactose oxidase from Dactylium dendroides has been used to prepare UDP-D-[ C]galacturonic acid and UDP-D-[6- H]galactose of high specific activity. ... 

Galactose oxidase is produced by the fungus Dactylium dendroides, recently renamed as a Fusarium spp. The amounts of enzyme produced by the wild-type Fusarium strains are, however, low. 

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