The fungus Gibberella fujikuroi produces copper/topaquinone‐containing amine oxidase when induced by n‐butylamine

Abstract

SUMMARYCrude extract of Gibberellafujikuroi AKU 3802 mycelium induced with n-butylamine showed a single amine oxidase activity band in a non-denaturing gel that cross-reacted with the antibody against copper/topaquinone-containing amine oxidase from AspergiUus niger. The enzyme was purified by a procedure involving four chromatographic steps. Purified enzyme was pink with an absorption maximum at 490 nm. Molecular mass of 135 kDa estimated by gel chromatography and 70 kDa found by SDS-PAGE confirmed the dimeric structure of the enzyme. The enzyme readily oxidized n-hexylamine, n-butylamine, benzylamine and histamine, but not spermine or spermidine. Inactivation by carbonyl reagents and copper chelators suggested the presence of a copper/topaquinone cofactor. Spectrophotometric titration by p-nitrophenylhydrazine showed one reactive carbonyl group per subunit and redox-cyclic quinone staining confirmed the presence of a quinone cofactor, pH-dependent shift of the absorption spectrum of the enzyme pnitrophenylhydrazone (465 nm at neutral to 580 nm at alkaline pH) supports the identity of the cofactor with topaquinone. The N-terminal amino acid sequence of the enzyme showed high similarity to other microbial copper/topaquinone-containing amine oxidases.

Degradation of biogenic amines by vineyard ecosystem fungi. Potential use in winemaking

“…In fungi, most of the amine oxidases have been studied in crude extracts when induced by various amines, mainly n ‐butylamine, methylamine, spermine and agmatine (Isobe et al. 1982; Frébort et al. 1997a).…”

“…In this survey, we have demonstrated for the first time the ability of vineyard ecosystem fungi to reduce the biogenic amines content in assay broth as well as in wines. In fungi, most of the amine oxidases have been studied in crude extracts when induced by various amines, mainly n-butylamine, methylamine, spermine and agmatine (Isobe et al 1982;Frébort et al 1997a). We selected 44 fungal strains representing the range of genera of fungi from a survey of grapevine ecosystems.…”

“…The ability to degrade biogenic amines was noteworthy for many fungi, independent of the amine incorporated into the culture medium (Table 3). These results are consistent with earlier data reported, where 88 fungi species from different origins and,including the genera Aspergillus sp., Fusarium sp., Mucor sp., Neurospora sp., and Monascus sp., among others, were induced with n-butylamine, methylamine or (Frébort et al 1997a). It is thought that amine oxidases allow the fungi to degrade an amine as a source of ammonium for growth; however, the role of these enzymes has not always been well defined (Frébort et al 2000).…”

“…1982). Two kinds of amine oxidases have been purified and characterized from fungi (Frébort et al. 1996, 1997a,b).…”

“…Several kinds of filamentous fungi are known to produce amine oxidase activity when using amines as a sole nitrogen source for growth (Yamada et al 1965(Yamada et al , 1966(Yamada et al , 1972Adachi and Yamada 1970;Isobe et al 1982). Two kinds of amine oxidases have been purified and characterized from fungi (Frébort et al 1996(Frébort et al , 1997a. Additionally, the genome of Aspergillus niger contains six genes encoding for amine oxidases.…”