title: High-performance liquid chromatography determination of enzyme activities in the presence of small amounts of product.
abstract: Enzymes can be assayed by HPLC by calculating the amount of substrate(s) left over, or product formed, through the peak area ratios with a suitable internal standard. However, sometimes the substrates used are contaminated with small amounts of products and this can lead to errors in the determination of the enzyme activity. A method for a HPLC test of such enzymes, which prevents eventual errors, uses the ratio substrate/product at time zero as internal standard and the kinetics can be followed with the aid of a simple mathematical equation. This approach was applied to the determination of the activities of papain, urokinase, NAD glycohydrolase, and pyruvate kinase samples and it was compared with the data obtained by the internal standard method, giving reproducible results in all cases.
authors.affiliation: Dipartimento di Scienze e Technologie Biomediche, University of Milano, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Pace
authors.forename: P
authors.initials: P
authors.lastname: Mauri
authors.forename: P
authors.initials: P
authors.lastname: Pietta
authors.forename: D
authors.initials: D
authors.lastname: Agnellini
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004798:Enzymes / Q000032:analysis* / Q000378:metabolism; D007700:Kinetics; D008433:Mathematics; D009243:NAD / Q000378:metabolism; D009244:NAD+ Nucleosidase / Q000032:analysis*; D009492:Neurospora crassa / Q000201:enzymology; D010206:Papain / Q000032:analysis / Q000378:metabolism; D011770:Pyruvate Kinase / Q000032:analysis / Q000378:metabolism; D013379:Substrate Specificity; D014568:Urokinase-Type Plasminogen Activator / Q000032:analysis / Q000378:metabolism
chemical_list: D004798:Enzymes; D009243:NAD; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D011770:Pyruvate Kinase; D009244:NAD+ Nucleosidase; D014568:Urokinase-Type Plasminogen Activator; D010206:Papain