Physiochemical Properties of Thermomycolase, the Thermostable, Extracellular, Serine Protease of the Fungus Malbranchea pulchella
| Autor: | Gerrit Voordouw, Rodney S. Roche, G. Maurice Gaucher |
|---|---|
| Rok vydání: | 1974 |
| Předmět: |
Protein Denaturation
Circular dichroism Hot Temperature Isoflurophate Time Factors Chemical Phenomena Macromolecular Substances Protein Conformation Globular protein Intrinsic viscosity chemistry.chemical_compound Drug Stability Endopeptidases Serine Actinomyces Sodium dodecyl sulfate Serine protease chemistry.chemical_classification Gel electrophoresis Binding Sites biology Chemistry Physical Viscosity Chemistry Circular Dichroism General Medicine Hydrogen-Ion Concentration Deuterium Molecular Weight Sedimentation coefficient Kinetics Biochemistry Sedimentation equilibrium biology.protein Calcium Electrophoresis Polyacrylamide Gel Spectrophotometry Ultraviolet Ultracentrifugation Protein Binding |
| Zdroj: | Canadian Journal of Biochemistry. 52:981-990 |
| ISSN: | 0008-4018 |
| DOI: | 10.1139/o74-137 |
| Popis: | The physicochemical properties of the extracellular protease of the fungus Malbranchea pulchella, for which we have adopted the name thermomycolase, were investigated. The molecular weight of diisopropylphosphorylthermomycolase was found to be 32 000–33 000 by sedimentation equilibrium and sodium dodecyl sulfate (SDS) gel electrophoresis. Its sedimentation coefficient (s020, w = 2.97 S), intrinsic viscosity ([η] = 3.0 cc/g), and frictional ratio (f/f0 = 1.09) characterize the enzyme as a typical globular protein. The circular dichroism spectrum of the protein is also consistent with its globular structure. Active thermomycolase autolyzes extensively, especially at low calcium ion concentrations, producing low molecular weight peptide material. In the presence of SDS, a different autolytic degradation is observed, resulting in much higher molecular weight polypeptide products (16 500, 12 500,11 000, 8 500). The results indicate that, in the presence of SDS, thermomycolase has three sites that are highly susceptible to autolysis. At calcium ion concentrations of 10−3 M and 10−2 M the enzyme undergoes a sharp thermal denaturation with transition temperatures at 69 °C and 75 °C, respectively, and with complete loss of enzyme activity. At 70 °C the enzyme appeared to be maximally thermostable at a calcium ion concentration of 10−2 M. |
| Databáze: | OpenAIRE |
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