Stabilization of ribonuclease B activity by concentrated xylose solutions.
Ribonuclease B has become a paradigm as a simple example of an N-linked glycoprotein. We have found that certain affinity-purified preparations of this enzyme demonstrated a pronounced tendency to lose activity if stored as dilute aqueous solutions. Such inactivation is accelerated by the presence of NaCl, but can be counteracted by inclusion of high (1 mol/l) concentrations of xylose. Enzyme activity cannot be restored by addition of xylose after storage of the enzyme. In marked contrast to alpha-methyl-mannoside, xylose does not prevent ribonuclease B from binding to concanavalin A and so may be used to stabilize the enzyme during purification by lectin affinity chromatography.
Department of Biological Sciences, Dublin Institute of Technology, Ireland.
G A
GA
Williams
U
U
MacEvilly
R
R
Ryan
M G
MG
Harrington
D002846:Chromatography, Affinity; D004795:Enzyme Stability; D007700:Kinetics; D008766:Methylmannosides / Q000494:pharmacology; D012260:Ribonucleases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D014994:Xylose / Q000494:pharmacology*
D008766:Methylmannosides; D012996:Solutions; C008466:methylmannoside; D014994:Xylose; D012260:Ribonucleases; C029600:ribonuclease B