Physicochemical Characteristics of a Thermostable Gellan Lyase from Geobacillus stearothermophilus 98
| Autor: | Anna Derekova, Miroslava Atanassova, Margarita Kambourova, Bojidar Tchorbanov, Rossitsa Mandeva, Petya Christova, Patricia Rodríguez-Alonso, J.I. Garabal, Alexandra Shosheva |
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| Rok vydání: | 2010 |
| Předmět: |
chemistry.chemical_classification
Gellan lyase Circular dichroism Stereochemistry Circular Dichroism Thermophile Substrate (chemistry) Bacillus Dichroism Crystallography X-Ray General Biochemistry Genetics and Molecular Biology Geobacillus stearothermophilus Kinetics Enzyme Differential scanning calorimetry chemistry Biochemistry Enzyme Stability Thermodynamics Electrophoresis Polyacrylamide Gel Chromatography Thin Layer Amino Acids Polysaccharide-Lyases |
| Zdroj: | Zeitschrift für Naturforschung C. 65:231-238 |
| ISSN: | 1865-7125 0939-5075 |
| Popis: | 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% β-structure and practically lack of α-spiral domains. Kinetic studies showed high affinity of the enzyme to gellan as a substrate (Km = 0.21 μM). The thermal denaturation investigated by cicular dichroism showed a highly cooperative transition with a midpoint (Tm) at about 75 °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. |
| Databáze: | OpenAIRE |
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