This document discusses enzyme engineering and provides details on enzymes, enzyme engineering, and the objectives and methods of enzyme engineering. Enzyme engineering aims to design enzymes by changing amino acid sequences through recombinant DNA technology. The main objectives are to produce enzymes with improved properties for industrial applications, such as increased thermostability, substrate specificity, or activity in organic solvents. The two main methods for enzyme engineering are rational design, which uses structural knowledge to make targeted changes, and directed evolution, which mimics natural evolution in vitro through random mutagenesis and selection of improved enzymes.
3. ENZYMES
Enzymes create chemical reaction in body.
They actually speed up the rate of a chemical reaction to support life.
The enzymes in your body perform very important tasks.
Building muscles
Destroying toxins
Breaking down food particles during digestion
An enzymes shape is tied to its function.
Heat, disease or harsh chemical conditions can damage enzymes and change their shapes.
When this happens, enzyme cannot work anymore.
4. ENZYME ENGINEERING
Enzyme engineering is the process of designing enzyme by changing the
sequence of amino acids through recombinant DNA technology.
These products will be useful as chemical , pharmaceutical, fuel, food or
agricultural additives.
Since enzymes are proteins, enzyme engineering is a part of the larger
activity of protein engineering.
Enzyme engineering utilizes r-DNA technology to introduce the desired
changes in amino acid sequences of enzymes
5. OBJECTIVES OF ENZYME ENGINEERING
The chief objective of enzyme engineering is to produce an enzyme that is more useful for
industrial and other applications.
The various properties of an enzyme that may be modified to achieve this objective are as
follows :-
Improved kinetic properties.
Elimination of allosteric regulation.
Enhanced substrate and reaction specificity.
Increased thermo stability.
Alteration in optimal pH.
Suitability for use in organic solvents.
Increased/decreased optimal temperature.
8. METHODS:
There are two general strategies for
enzyme engineering:
Rational design
Directed evolution
9. RATIONAL DESIGN
It is the earlier approach to enzyme engineering and still is widely used.
In rational design, scientist uses detailed knowledge of structure and function of a protein to
make desired changes.
In general, it has a advantage of being inexpensive and technically easy.
However, the major drawback is that a detailed structural knowledge of enzyme is often
unavailable.
Even when available, it can be very difficult to predict the effects of various mutations since
structural information most often provide a static picture of enzyme structure.
Two methods in rational design
Overlap extension
Whole plasmid single round PCR
10.
11. DIRECTED EVOLUTION:
Also termed
In vitro evolution
Directed molecular evolution
Acceleration evolution
Directed evolution(DE) encompasses several molecular techniques that mimic the process
of Darwinian evolution in vitro, by combining random mutagenesis or recombinant
Technology.
It does not uses structural data of enzyme, other than its functional properties and its
corresponding DNA sequence.
DE is sometimes referred to irrational or semi-rational design.
12. Directed evolution
Mimick recombination: DNA shuffling
With restriction enzymes:
1. Digest family of related genes
2. DNA ligase to join fragments
3. Chimeric genes