STABILIZERS FOR ENZYMES (mainly XYLANASE)Methods Digest, Vol 45, Issue 7

Dr Engelbert Buxbaum via (by engelbert_buxbaum from
Sun Feb 15 07:39:38 EST 2009

Am 11.02.2009, 15:29 Uhr, schrieb whyharish reddy <whyharish from>:

> *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 (, 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.

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