Lecture 2 Flashcards
Protein Engineering
What are the 3 uses of industrial enzymes
Industry, Environmental and Agriculture
Name some examples of industrial enzymes in industry
Detergents, textiles, chemicals, pharmaceuticals, food processing, protein hydrolysis, starch processing, biofuels
Name some examples of industrial enzymes in environment uses
Degradation of residual waste, detoxification of toxic substances
Name some examples of industrial enzymes in agriculture uses
Feed processing, Animal feed additives and agro-processing
What does Km mean
An indicator of affinity. The higher the Km value the lower the affinity
What does Vmax mean
The maximal rate of conversion of a substrate to the products
What does Kcat mean
A measure of how quickly a given enzyme can catalyse a specific reaction
What is the enzyme efficiency equation
Efficiency= Kcat/Km
units= M-1 Sec-1
What can you do to create proteins with an extended industrial application
Change the pH of protein or change thermal stability (adding S-S or reducing the number of free S-H bonds)
What are characteristics of the Hen lysozyme
- Two domains (alpha and beta)
- Thermostability of the naturally occurring enzyme comes from 4 S-S bonds
- Gene for the enzyme was mutated so different S-S bridges were unable to form- protein becomes unstructured.
What mutation occurred to cocaine hydrolysis
6 amino acid residues in the active site were replaced
What mutation occurred to Subtilisin (washing detergent)
Changed catalytic activity, substrate specificity and pH profile. Under oxidising conditions, Met222 undergoes oxidation to a sulphone.
What mutation occurred to Natokinase
Effect on activity depends on position of substitution in the polypeptide chain. QE variants displayed reduced activity following acidic treatment
What mutation occurred to Xylanase (paper making)
Bleaching process is used to remove hemicellulose from pump and can be enhanced using xylanase. Enhanced thermostability and alkali treatment
