Naslov
Crystal structure of a fungal deglycating enzyme, fructosyl-amino acid oxidase (Amadoriase II)

Autori
Collard, Francois ; Zhang, Jianye ; Nemet, Ina ; Sayre, Lawrence A. ; Yee, Vivien C. ; Monnier, Vincent M.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
9th International Symposium on the Maillard Reaction. Book of Abstracts / - München : IMARS, 2007, 157-157

Skup
9th International Symposium on the Maillard Reaction

Mjesto i datum
München, Njemačka, 01.09.2007. - 05.09.2007

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
crystal structure; fructosyl-amino acid oxidase; Amadoriase II

Sažetak
Fructosyl-amino acid oxidases (FAOX) are bacterial and fungal enzymes that oxidize low molecular weight fructosamines at the C-N bond that link the fructose moiety to the amine. The Schiff base formed is unstable and hydrolyzes with the concomittant release of glucosone and the amine in its pristine stage. FAOX's can therefore be considered as deglycating enzymes ; however, these enzymes do not display activity toward glycated proteins. BLAST searches in fungi and evolutionary tree analysis indicated the presence of at least four different types of FAOX, that vary in their affinities for fructosamines depending on whether the sugar portion is linked to the amine bound to the carbon alpha or epsilon of the amino-acid. We report here the crystal structure of FAOX2 from A. fumigatus at 1.6 &Aring ; resolution in complex with an inhibitor, fructosyl-thioacetate. The structure of FAOX2 is very similar to sarcosine oxidase, its closest homologue. Comparison of the structure of FAOX2 with and without the inhibitor indicates conformational changes of the protein upon binding of the inhibitor. Residues potentially involved in substrate binding and specificity, FAD redox potential enhancement and conformational changes were identified and their roles are being investigated by mutagenesis. Measurements indicated that the active site is buried more than 15 &Aring ; under the surface of the enzyme, providing a possible explanation for the lack of activity of FAOX toward glycated proteins.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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