Data/hora: 13/06/2024 11:04:39

Provedor de dados: 	5	
País: 	France	
Título: 	Characterization of a highly thermostable alkaline phosphatase from the euryarchaeon Pyrococcus abyssi	
Autores: 	Zappa, Sebastien; Rolland, Jean-luc; Flament, Didier; Gueguen, Yannick; Boudrant, Joseph; Dietrich, Jacques.	
Data: 	2001-10	
Ano: 	2001	
Palavras-chave: 	Escherichia coli; Characterization; Isolation; Gene; Alkaline phosphatase; Pyrococcus abyssi; Archaeon.	
Resumo: 	This work reports the first isolation and characterization of an alkaline phosphatase (AP) from a hyperthermophilic archaeon. An AP gene from Pyrococcus abyssi, a euryarchaeon isolated from a deep-sea hydrothermal vent, was cloned and the enzyme expressed in Escherichia coli. Analysis of the sequence showed conservation of the active site and structural elements of the E. coli AP. The recombinant AP was purified and characterized. Monomeric and homodimeric active forms were detected, with a monomer molecular mass of 54 kDa. Apparent optimum pH and temperature were estimated at 11.0 and 70 degreesC, respectively. Thus far, P. abyssi AP has been demonstrated to be the most thermostable AP, with half-lives at 100 and 105 degreesC of 18 and 5 h, respectively. Enzyme activity was found to be dependent on divalent cations: metal ion chelators inhibited activity, whereas the addition of exogenous Mg(II), Zn(II), and Co(II) increased activity. The enzyme was inhibited by inorganic phosphate, but not by molybdate and vanadate. Strong inhibitory effects were observed in the presence of thiol-reducing agents, although cysteine residues of the P. abyssi AP were not found to be incorporated within intra-or interchain disulfide bonds. In addition, P. abyssi AP was demonstrated to dephosphorylate linear DNA fragments with dephosphorylation efficiencies of 93.8 and 84.1 % with regard to cohesive and blunt ends, respectively.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	http://archimer.ifremer.fr/doc/2001/publication-1268.pdf

DOI:10.1128/AEM.67.10.4504-4511.2001	
Editor: 	American society for microbiology	
Relação: 	http://archimer.ifremer.fr/doc/00000/1268/	
Formato: 	application/pdf	
Fonte: 	Applied and environmental microbiology (0099-2240) (American society for microbiology), 2001-10 , Vol. 67 , N. 10 , P. 4504-4511	
Fonte: 	2001, American Society for Microbiology. All rights reserved