Physicochemical characteristics of a thermostable gellan lyase from Geobacillus stearothermophilus 98.
Z Naturforsch C J Biosci
; 65(3-4): 231-8, 2010.
Article
em En
| MEDLINE
| ID: mdl-20469643
ABSTRACT
A purified thermostable gellan lyase, produced by a thermophilic bacterium, Geobacillus stearothermophilus 98, was characterized in relation to its physicochemical properties. The gellan lyase was established to have a molecular weight of 216 kDa, defined by capillary gel electrophoresis. Amino acid analysis revealed high quantities of Lys, His, Ala, Val, Ile, Glx, and Pro residues. The circular dichroism revealed 45% beta-structure and practically lack of a-spiral domains. Kinetic studies showed high affinity of the enzyme to gellan as a substrate (Km = 0.21 microM). The thermal denaturation investigated by cicular dichroism showed a highly cooperative transition with a midpoint (Tm) at about 75 degrees C. A single product was identified after enzyme action on gellan. Large exothermic aggregation near Tm was observed by differential scanning calorimetry. Two types of gellan lyase crystals were reproducibly isolated.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Polissacarídeo-Liases
/
Bacillus
/
Geobacillus stearothermophilus
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Z Naturforsch C J Biosci
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Bulgária