title: Cloning, purification and characterisation of a recombinant purine nucleoside phosphorylase from Bacillus halodurans Alk36.
abstract: A purine nucleoside phosphorylase from the alkaliphile Bacillus halodurans Alk36 was cloned and overexpressed in Escherichia coli. The enzyme was purified fivefold by membrane filtration and ion exchange. The purified enzyme had a V (max) of 2.03 x 10(-9) s (-1) and a K (m) of 206 microM on guanosine. The optimal pH range was between 5.7 and 8.4 with a maximum at pH 7.0. The optimal temperature for activity was 70 degrees C and the enzyme had a half life at 60 degrees C of 20.8 h.
authors.affiliation: Enzyme Technologies Group, CSIR Biosciences, Private Bag X2, Modderfontein, Johannesburg, 1645, South Africa.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Visser
authors.forename: Fritha
authors.initials: F
authors.lastname: Hennessy
authors.forename: Konanani
authors.initials: K
authors.lastname: Rashamuse
authors.forename: Maureen E
authors.initials: ME
authors.lastname: Louw
authors.forename: Dean
authors.initials: D
authors.lastname: Brady
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D011683:Purine-Nucleoside Phosphorylase / Q000235:genetics* / Q000302:isolation & purification* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D040681:Structural Homology, Protein; D013816:Thermodynamics
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial; D011994:Recombinant Proteins; D011683:Purine-Nucleoside Phosphorylase