title: Thermodynamic characterization of a highly thermoactive extracellular pectate lyase from a new isolate Bacillus pumilus DKS1.
abstract: An extracellular pectate lyase (EC 4.2.2.2) was purified from the culture filtrate of a newly isolated Bacillus pumilus DKS1 grown in pectin containing medium. Using ion-exchange and gel filtration chromatography, this enzyme was purified and found to have a molecular weight of around 35kDa. The purified enzyme exhibited maximal activity at a temperature of 75 degrees C and pH 8.5. The presence of 1mM calcium and manganese enhanced pectate lyase activity and was strongly inhibited by zinc, nickel and EDTA. The thermal inactivation studies revealed an entropy-enthalpy compensation pattern below a critical temperature. The alkaliphilicity and high thermostability of this pectate lyase may have potential implications in fibre degumming.
authors.affiliation: Department of Biochemistry, University College of Science, Calcutta University, 35 Ballygunge Circular Road, West Bengal, Kolkata 700 019, India.
authors.forename: Snehasish
authors.initials: S
authors.lastname: Basu
authors.forename: Abhrajyoti
authors.initials: A
authors.lastname: Ghosh
authors.forename: Amit
authors.initials: A
authors.lastname: Bera
authors.forename: Manabendra N
authors.initials: MN
authors.lastname: Saha
authors.forename: Dhrubajyoti
authors.initials: D
authors.lastname: Chattopadhyay
authors.forename: Krishanu
authors.initials: K
authors.lastname: Chakrabarti
mesh_terms: D001407:Bacillus / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification*; D001665:Binding Sites; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D019277:Entropy; D004789:Enzyme Activation / Q000187:drug effects; D005110:Extracellular Space / Q000187:drug effects / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D008969:Molecular Sequence Data; D010368:Pectins / Q000378:metabolism; D011133:Polysaccharide-Lyases / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D017433:Protein Structure, Secondary; D013696:Temperature; D013816:Thermodynamics; D014364:Tryptophan
chemical_list: D008670:Metals; D010368:Pectins; D014364:Tryptophan; D011133:Polysaccharide-Lyases; C023911:pectate lyase