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Modulation of egg-white lysozyme activity by viscosity intensifier additives
L Lamy1, M O Portmann, M Mathlouthi
1Laboratoire de Technologie Enzymatique, Université de Compiègne, France.
Biophysical Chemistry
|May 1, 1990
Summary
Egg-white lysozyme activity decreases with carbohydrate additives that increase viscosity. Enzyme behavior remains Michaelian, with viscosity effects varying based on additive concentration and type.
Area of Science:
- Biochemistry
- Enzyme kinetics
- Physical chemistry
Background:
- Enzyme activity is influenced by reaction medium properties.
- Carbohydrate additives alter water activity and viscosity.
- Understanding these effects is crucial for enzyme applications.
Purpose of the Study:
- To investigate the impact of carbohydrate additives on egg-white lysozyme activity.
- To characterize solute-solvent interactions in additive solutions.
- To determine the relationship between medium viscosity and enzyme kinetics.
Main Methods:
- Enzyme activity assays of egg-white lysozyme.
- Measurement of solution viscosity and water activity.
- Characterization of solute-solvent interactions (intrinsic viscosity, Huggins constant, etc.).
Main Results:
- Carbohydrate additives decreased lysozyme activity and water activity while increasing viscosity.
- Enzyme kinetics remained Michaelian, with no change in Km or substrate inhibition.
- Viscosity effects on activity were independent of additive type at high viscosities (>4 mPa·s) but varied at low viscosities (<2 mPa·s).
Conclusions:
- Carbohydrate additives modulate lysozyme activity primarily through viscosity changes.
- The influence of viscosity on enzyme kinetics is concentration-dependent and additive-specific.
- Lysozyme maintains its fundamental kinetic behavior even under altered solution conditions.