Related Experiment Videos
Further characterization and kinetic parameter determination of a milk-clotting protease from Mucor bacilliformis
G D Venera1, C Machalinski, H Zumárraga
1Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Facultad de Farmacía y Bioquímíca, Buenos Aires, Argentina.
Abstract:
Further characterization of an aspartyl protease from Mucor bacilliformis with milk-clotting activity was performed. An extinction coefficient, epsilon 278 cm = 1.61 mL/mg/cm, a molecular mass of 35,400 Da and a pI of 5.2 were determined. Proteolytic activity and kinetic parameters were evaluated by using the hexapeptide Leu-Ser-pNO2-Phe-Nle-Ala-Leu-OMe as the substrate. The effect of pH and temperature on peptide cleavage, as well as protease heat stability, was determined. Such properties, taken as a whole, indicate that the M. bacilliformis protease can be considered a potential substitute for bovine chymosin in cheese manufacture.
Insights
This study characterizes a Mucor bacilliformis aspartyl protease, revealing properties suitable for cheese production. The findings suggest this microbial protease could replace traditional bovine chymosin in dairy applications.
Area of Science:
- Biochemistry
- Enzymology
- Food Science
Background:
- Aspartyl proteases are crucial enzymes in food processing, particularly in cheese manufacture.
- Bovine chymosin is the standard enzyme for milk clotting, but alternatives are sought for economic and ethical reasons.
Purpose of the Study:
- To further characterize the milk-clotting aspartyl protease from Mucor bacilliformis.
- To evaluate its biochemical and kinetic properties for potential use in cheese production.
Main Methods:
- Determination of extinction coefficient, molecular mass, and isoelectric point (pI).
- Evaluation of proteolytic activity and kinetic parameters using a specific hexapeptide substrate.
- Assessment of the enzyme's stability and activity under varying pH and temperature conditions.
Main Results:
- The Mucor bacilliformis protease exhibited an extinction coefficient of 1.61 mL/mg/cm, a molecular mass of 35,400 Da, and a pI of 5.2.
- Proteolytic activity and kinetic parameters were successfully evaluated.
- The enzyme's heat stability and optimal conditions for peptide cleavage were determined, indicating suitability for industrial applications.
Conclusions:
- The characterized aspartyl protease from Mucor bacilliformis possesses properties favorable for milk-clotting activity.
- This microbial protease shows potential as a viable and effective substitute for bovine chymosin in the cheese-making industry.