Advanced

Structural and functional characterization of ochratoxinase, a novel mycotoxin-degrading enzyme

Dobritzsch, Doreen; Wang, Huaming; Schneider, Gunter and Yu, Shukun LU (2014) In Biochemical Journal 462. p.441-452
Abstract
Ochratoxin, with ochratoxin A as the dominant form, is one of the five major mycotoxins most harmful to humans and animals. It is produced by Aspergillus and Penicillium species and occurs in a wide range of agricultural products. Detoxification of contaminated food is a challenging health issue. In the present paper we report the identification, characterization and crystal structure (at 2.2 angstrom) of a novel microbial ochratoxinase from Aspergillus niger. A putative amidase gene encoding a 480 amino acid polypeptide was cloned and homologously expressed in A. niger. The recombinant protein is N-terminally truncated, thermostable, has optimal activity at pH similar to 6 and 66 degrees C, and is more efficient in ochratoxin A hydrolysis... (More)
Ochratoxin, with ochratoxin A as the dominant form, is one of the five major mycotoxins most harmful to humans and animals. It is produced by Aspergillus and Penicillium species and occurs in a wide range of agricultural products. Detoxification of contaminated food is a challenging health issue. In the present paper we report the identification, characterization and crystal structure (at 2.2 angstrom) of a novel microbial ochratoxinase from Aspergillus niger. A putative amidase gene encoding a 480 amino acid polypeptide was cloned and homologously expressed in A. niger. The recombinant protein is N-terminally truncated, thermostable, has optimal activity at pH similar to 6 and 66 degrees C, and is more efficient in ochratoxin A hydrolysis than carboxypeptidase A and Y, the two previously known enzymes capable of degrading this mycotoxin. The subunit of the homo-octameric enzyme folds into a two-domain structure characteristic of a metal dependent amidohydrolase, with a twisted TIM (triosephosphateisomerase)-barrel and a smaller beta-sandwich domain. The active site contains an aspartate residue for acid base catalysis, and a carboxylated lysine and four histidine residues for binding of a binuclear metal centre. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
metal-dependent amidohydrolase, mycotoxin, ochratoxin degradation, protein crystal structure
in
Biochemical Journal
volume
462
pages
441 - 452
publisher
Portland Press Limited
external identifiers
  • wos:000341802100006
  • scopus:84907311620
ISSN
0264-6021
DOI
10.1042/BJ20140382
language
English
LU publication?
yes
id
c761aeac-b34e-4565-9ad5-5010ac23f901 (old id 4702685)
date added to LUP
2014-10-23 10:22:16
date last changed
2017-01-01 05:51:56
@article{c761aeac-b34e-4565-9ad5-5010ac23f901,
  abstract     = {Ochratoxin, with ochratoxin A as the dominant form, is one of the five major mycotoxins most harmful to humans and animals. It is produced by Aspergillus and Penicillium species and occurs in a wide range of agricultural products. Detoxification of contaminated food is a challenging health issue. In the present paper we report the identification, characterization and crystal structure (at 2.2 angstrom) of a novel microbial ochratoxinase from Aspergillus niger. A putative amidase gene encoding a 480 amino acid polypeptide was cloned and homologously expressed in A. niger. The recombinant protein is N-terminally truncated, thermostable, has optimal activity at pH similar to 6 and 66 degrees C, and is more efficient in ochratoxin A hydrolysis than carboxypeptidase A and Y, the two previously known enzymes capable of degrading this mycotoxin. The subunit of the homo-octameric enzyme folds into a two-domain structure characteristic of a metal dependent amidohydrolase, with a twisted TIM (triosephosphateisomerase)-barrel and a smaller beta-sandwich domain. The active site contains an aspartate residue for acid base catalysis, and a carboxylated lysine and four histidine residues for binding of a binuclear metal centre.},
  author       = {Dobritzsch, Doreen and Wang, Huaming and Schneider, Gunter and Yu, Shukun},
  issn         = {0264-6021},
  keyword      = {metal-dependent amidohydrolase,mycotoxin,ochratoxin degradation,protein crystal structure},
  language     = {eng},
  pages        = {441--452},
  publisher    = {Portland Press Limited},
  series       = {Biochemical Journal},
  title        = {Structural and functional characterization of ochratoxinase, a novel mycotoxin-degrading enzyme},
  url          = {http://dx.doi.org/10.1042/BJ20140382},
  volume       = {462},
  year         = {2014},
}