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Study of the Enzymatic Activity of Arthrobacter ureafaciens Neuraminidase by Isothermal Titration Calorimetry
Author(s) -
Chen ChienSheng,
Lee WeiJen
Publication year - 2018
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201700303
Subject(s) - chemistry , isothermal titration calorimetry , michaelis–menten kinetics , gibbs free energy , enthalpy , activation energy , entropy of activation , titration , hydrolysis , sialic acid , calorimetry , enzyme , enzyme kinetics , neuraminidase , chromatography , reaction rate constant , biochemistry , enzyme assay , kinetics , thermodynamics , active site , physics , quantum mechanics
Isothermal titration calorimetry was used to determine the enzymatic activity and thermodynamic activation parameters of Arthrobacter ureafaciens sialidase with the sialyl substrates α‐2,3‐, α‐2,6‐sialyllactoses and α‐2,8‐sialic acid dimer. By monitoring the heat released during hydrolysis, the Michaelis constant ( K m ), catalytic rate constant ( k cat ), activation energy, activation Gibbs energy, enthalpy, and entropy for different monovalent sialyl conjugates were calculated and found to be consistent with those derived by chromatographic or colorimetric assays. The observed decreases in the activation energy and transition entropy of sialyllactoses were larger than the Michaelis activation parameters of lactose‐free di‐sialic acid because of the specific enzyme activity of A. ureafaciens sialidase.