Article (Scientific journals)
Cold-Adapted Beta-Galactosidase from the Antarctic Psychrophile Pseudoalteromonas Haloplanktis
Hoyoux, A.; Jennes, I.; Dubois, P. et al.
2001In Applied and Environmental Microbiology, 67 (4), p. 1529-35
Peer Reviewed verified by ORBi
 

Files


Full Text
AEM_2001_betagal.pdf
Publisher postprint (260.86 kB)
Download

All documents in ORBi are protected by a user license.

Send to



Details



Abstract :
[en] The beta-galactosidase from the Antarctic gram-negative bacterium Pseudoalteromonas haloplanktis TAE 79 was purified to homogeneity. The nucleotide sequence and the NH(2)-terminal amino acid sequence of the purified enzyme indicate that the beta-galactosidase subunit is composed of 1,038 amino acids with a calculated M(r) of 118,068. This beta-galactosidase shares structural properties with Escherichia coli beta-galactosidase (comparable subunit mass, 51% amino sequence identity, conservation of amino acid residues involved in catalysis, similar optimal pH value, and requirement for divalent metal ions) but is characterized by a higher catalytic efficiency on synthetic and natural substrates and by a shift of apparent optimum activity toward low temperatures and lower thermal stability. The enzyme also differs by a higher pI (7.8) and by specific thermodynamic activation parameters. P. haloplanktis beta-galactosidase was expressed in E. coli, and the recombinant enzyme displays properties identical to those of the wild-type enzyme. Heat-induced unfolding monitored by intrinsic fluorescence spectroscopy showed lower melting point values for both P. haloplanktis wild-type and recombinant beta-galactosidase compared to the mesophilic enzyme. Assays of lactose hydrolysis in milk demonstrate that P. haloplanktis beta-galactosidase can outperform the current commercial beta-galactosidase from Kluyveromyces marxianus var. lactis, suggesting that the cold-adapted beta-galactosidase could be used to hydrolyze lactose in dairy products processed in refrigerated plants.
Disciplines :
Biochemistry, biophysics & molecular biology
Author, co-author :
Hoyoux, A.
Jennes, I.
Dubois, P.
Genicot, S.
Dubail, F.
François, Jean-Marie ;  Université de Liège - ULiège > Département des sciences de la vie > Macromolécules biologiques
Baise, Etienne ;  Université de Liège - ULiège > Département des sciences de la vie > Macromolécules biologiques
Feller, Georges ;  Université de Liège - ULiège > Département des sciences de la vie > Labo de biochimie
Gerday, Charles ;  Université de Liège - ULiège > Services généraux (Faculté des sciences) > Relations académiques et scientifiques (Sciences)
Language :
English
Title :
Cold-Adapted Beta-Galactosidase from the Antarctic Psychrophile Pseudoalteromonas Haloplanktis
Publication date :
April 2001
Journal title :
Applied and Environmental Microbiology
ISSN :
0099-2240
eISSN :
1098-5336
Publisher :
American Society for Microbiology, Washington, United States - District of Columbia
Volume :
67
Issue :
4
Pages :
1529-35
Peer reviewed :
Peer Reviewed verified by ORBi
Available on ORBi :
since 26 January 2010

Statistics


Number of views
73 (7 by ULiège)
Number of downloads
112 (5 by ULiège)

Scopus citations®
 
155
Scopus citations®
without self-citations
149
OpenCitations
 
144

Bibliography


Similar publications



Contact ORBi