Dactylium dendroides

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... 

An increased SOD capacity after copper supply was also found in other organisms (Shatzman and Kosman, 1978, in the fungus Dactylium dendroides Naiki, 1980, Sac-charomyces Ljutakova et al., 1984, rat liver Lee and Hassan, 1985, Saccharomyces). The increased biosynthesis of SOD in copper-treated yeast was suggested to be the result of an enhanced intracellular 02 flux (Lee and Hassan, 1985). 

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. 

Crook and Johnston and Martin and Adams were unable to find uronic acids in the cell walls of fungi. However, 2 % of a glucuronic acid was detected in the dry cells of Dactylium dendroides, and lesser proportions in Aspergillus niger (0.1 %), Penicillium album (0.2%), a Fusarium sp. (0.5%), and an Alternaria sp. (0.7%). Glucuronic acid residues are apparently present in the cell walls of Neurospora crassa. ... 

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]. 

Domain 1 contains the first 8 -strands as well as a binding site for a sodium ion and for D-galactose. It is yet unknown whether the sodium ion is of importance for the enzyme s function. Domain 1 is of some distance from the copper center and its function is not clearly defined. It is possibly a chaperone for the correct folding of the enzyme, in which domain 1 is utilized as a blueprint for the complicated folding of domain 2. The D-galactose binding site of domain 1 may possibly be needed to attach the enzyme to the cell walls of trees, the natural habitat of Dactylium dendroides [30]. 

Figure 4 Type-2 copper site in gaiactose oxidase from Dactylium dendroides (PDB-code 1GOG) prepared with PyMOL (W. L. Delano, Paio Aito, 2003).

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... 

Figure 14 Ribbon diagram of gaiactose oxidase from Dactylium dendroides (PDB-code 1GOG). The coiors of the individuai domains are domain 1 (1-155), biue domain 2 (156-532), pink domain 3 (533-639), red prepared with PyMOL (W. L. Delano, Paio Aito, 2003).

Spores of Dactylium dendroides are killed when exposed to 115-l22°F. for only Vz hour. (See Anderson, 1956). The genus Dacily/aria is synonomous with Dactylium. Several species are known for their specialization in trapping nematodes by arranging their hyphae into loose coils. When one enters a loop, the hypha contract and traps the nematode. 

Berkessel et al. took a diversity-based approach to the discovery of functional models for GOase 42). Based on the known coordination pattern of the catalytically active copper ion (X-ray crystal structure of GOase from Dactylium dendroides, schematically in Scheme 12), the peptide/peptoid library 29 (Scheme 13) was designed. In this library, the Gly-D-Pro-turn positions the four amino acids X -X such that they can coordinate a copper ion. The four positions X X were occupied, in a combinatorial manner, by either histidine, tyrosine, the Cys22s-Tyr272-model mod-Cys (30), and in particular the TEMPO-derived amino acid TOAC (31) (Scheme 13). Thus, the TOAC-derived library comprised a total of 81 decapeptides, and it was synthesized... 

Hydroxylation and deacetylation of 16a-methyl-17a,21-dihydroxy-4-pregnene-8,20-dione 21-acetate with Rhizopus nigricans. lla-Hydroxylation and deacetylation of the same substrate with Dactylium dendroides. 

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. ... 

C. Kemmelmeier, and G.T. Zancan, Chemical and immunological properties of galacto-glucomannans from Dactylium dendroides, Exp. Mycol., 5 (4), 339-348, 1981. 

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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