Abstract
Amino groups in alpha-chymotrypsin were reacted with pyromellitic anhydride, introducing 17 to 32 additional carboxyl groups. This modification causes a major change in the water adsorption isotherm of the lyophilized protein powder. Little water is bound by the modified enzyme at water activity (a(w)) below 0.35, but it shows increased water binding at a(w) over 0.5. This correlates with a similar change in the a(w) dependence of the catalytic activity of the enzyme powder suspended in hexane, with a much steeper increase in activity of the modified chymotrypsin.
Original language | English |
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Pages (from-to) | 161-166 |
Number of pages | 5 |
Journal | Biocatalysis and Biotransformation |
Volume | 20 |
Issue number | 3 |
DOIs | |
Publication status | Published - Jun 2002 |
Keywords
- water adsorption
- low-water nonpolar media
- chymotrypsin
- chemical modification
- pyromellitic acid
- Organic media
- alpha-chymotrypsin
- enzyme-activity
- stability
- solvents
- protein
- esterification