Solubilization, stabilization and isoelectric focusing of human liver neuraminidase activity.

Publication/Presentation Date

7-30-1984

Abstract

Homogenate preparations of human liver have been prepared and over 75% of the particulate neuraminidase activity (which comprises approx. 90% of the total activity) has been solubilized using 0.85% (w/v) Triton X-100 in 25 mM phosphate buffer (pH 6.8). The solubilized neuraminidase activity is extremely labile, but can be stabilized for at least 4 weeks at 2-4 degrees C, using 10 mM N-acetylneuraminic acid. Kinetic characterization of homogenate and solubilized supernatant fluid neuraminidase activities indicated comparable pH optimum curves (maximum activity at pH 4.5-4.7) and apparent Km values (0.2-0.4 mM) for the synthetic fluorometric substrate 4-methylumbelliferyl-alpha-D-N-acetylneuraminic acid. Isoelectric focusing has been performed on human liver homogenates and Triton X-100-solubilized neuraminidase activities, and the presence of several forms (4-6) with isoelectric points (pI values) between 4.4 and 5.2 has been demonstrated in both preparations. The similar kinetic and isoelectric focusing properties of the two preparations suggest that the solubilized enzyme activity is representative of the homogenate activity and that the solubilized enzyme is suitable for purification purposes.

Volume

800

Issue

2

First Page

159

Last Page

165

ISSN

0006-3002

Disciplines

Medicine and Health Sciences

PubMedID

6743688

Department(s)

Department of Medicine

Document Type

Article

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