Bubbles in bread - Opportunities for psychrophilic endo-xylanases as bread improver
8 important questions on Bubbles in bread - Opportunities for psychrophilic endo-xylanases as bread improver
Aspergillus GH10 and GH11 endo-xylanases are mesophilic enzymes, what does that mean?
What are psychrophilic enzymes?
Why is the use of psychrophilic enzymes more useful than mesophilic enzymes?
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
What are thermophilic enzymes?
Are psychrophilic, mesophilic and thermophilic enzymes sensitive to unfolding?
- Psychrophilic --> very sensitive to unfolding and consequently inactivation
- Thermophilic --> stable against unfolding
- Mesophilic --> intermediate position between the two with respect to unfolding
Do psychrophilic enzymes have a broad substrate-binding groove to facilitate substrate-binding?
What is the difference between psychrophilic and thermophilic enzymes?
- The active site of psychrophilic enzyme displays much higher flexibility, which facilitates substrate-binding in low temperature environment, where diffusion is slower.
- The increased flexibility is associated with the reduced thermostability of these enzymes.
- The amino acids forming subsites +1 and +2 dramatically alter their orientation upon binding of substrate. In the active site, amino acids can move around freely in order to help capture the substrate.
- Reduced number of salt bridges
- Increased exposure of hydrophobic residues
- This adaptability of the active site is typical for psychrophilic enzymes. It seems as if these enzymes actively catch the substrate.
How have thermophilic enzymes adapted to cope with elevated temperatures?
- By disulfide cross-linking of cysteine residues
- Structural stabilization by calcium ions
- Salt bridges
- Stable against unfolding at high T
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
![Trustpilot Logo](/images/design_2020/lp/clp-trustpilot-en.png)