STABILIZERS FOR ENZYMES (mainly XYLANASE)Methods Digest, Vol 45,
Dr Engelbert Buxbaum
(by engelbert_buxbaum from hotmail.com)
Sun Feb 15 07:39:38 EST 2009
Am 11.02.2009, 15:29 Uhr, schrieb whyharish reddy <whyharish from gmail.com>:
> *I am unable to maintain my enzyme activity not more than 2 days, *
> *please help in mainatining the activity of XYLANASE ENZYME for more than
> 2-3 months, suggest some Enzyme Stablizers?*
Have you done a literature search (scholar.google.com, PubMed)? Of hand I
can help only with some general hints:
- Stability is temperature dependent. As is generally known, enzymes can
be heat-denatured, but some are also cold-denatured.
- Stability is strongly pH-dependent. Avoid storing enzymes near the pI,
and at extreme pH values. Other than that, trial and error.
- Some enzymes are sensitive to ionic strength and osmotic pressure. Keep
both near physiological values. For intracellular enzymes use KCl, for
extracellular NaCl to adjust ionic strenght. Manitol, sucrose, glycerol or
similar polyols are used to maintain osmotic pressure.
- Some enzymes require specific cofactors for activity and may be
stabilised in their presence. Mg, Zn...
- Sterile filter your preparation using a low-protein binding membrane
(0.22 µm) and use aseptic techniques for handling. Add presevatives (Na
azide, Thimerosal...) but check that they are compatible with the enzyme.
- Check an inactive preparation for what actually happend, for example by
SDS-PAGE, light scattering and CD-spectroscopy. Is the enzyme degraded
(presence of proteolytic enzymes, microorganisms), forms aggregates or
changes conformation? That info can help you develop more targeted
approaches to the problem.
More information about the Methods