Abstract
Frog liver (Rana esculenta) is a rich source of acylneuraminate cytidylyltransferase. The soluble enzyme was purified 250-fold almost to purity with 25% yield and a specific activity of 9 mkat/kg protein (0.54 U/mg protein) using DEAE Sephadex and Sepharose 6B chromatography, followed by preparative polyacrylamide gel electrophoresis. The molecular weight of the cytidylyltransferase was determined to be 163 000 with the aid of Sepharose 6B chromatography and gel electrophoresis, with or without dodecyl sulphate or urea. No subunits were found. The isoelectric point of the enzyme is at pH 6. Optimum reaction rate was observed at pH 9, 37 degrees C, 50mM Mg2 or Ca2 and ImM mercaptoethanol. The Km values for N-acetylneuraminic acid, N-glycoloylneuraminic acid and CTP are 1.6mM, 2.3 mM and 0.6mM, respectively. O-Acetylated sialic acids are inactive with the cytidylyltransferase from frog liver. Enzyme activity can be inhibited by SH reagents and CMP (Ki = 0.5mM).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Hoppe-Seyler's Zeitschrift fur physiologische Chemie
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
