Artificial enzymes

1. Presented By,
Meiyarasu A,
Maheswari R,
Sneha S,
Jayasri V.

2.  Enzymes are biological catalysts.
 A Catalyst is defined as “a substance that
increases the rate of chemical reaction without
being itself changed in the process”.
Enzymes as Biological Catalysts:
 Enzymes are proteins that increase the rate of
reaction by lowering the energy of activation .
 They catalyze nearly all the chemical reaction
taking place in the cell of the body.
 Enzymes have unique three dimensional shapes
that fit the shapes of the reactants (substrates).

3.  Catalytic Efficiency – High efficiency , 103 t0
1017 faster than the corresponding catalyzed
reactions .
 Specificity - High efficiency specific
specificity, interacting with one or few
specific substrates and catalysing only one
type of chemical reaction.
 Mild Reaction Condition: 37 degree celcius ,
physiological pH , ambient atmospheric
pressure.

4.  Artificial Enzyme may be defined as the synthetic, organic
molecule prepare to recreate/mimic the active site of an natural
enzyme.
 The binding of a substrate close to functional groups in the
enzyme causes catalysis by so called proximity effects.
 It is therefore possible to create similar catalysts from small
molecule which will mimics the enzyme active sites.
 Since the artificial enzymes need to bind molecules, they are
based on the host molecule such as Cyclodextrins, crown ethers
or calixarence etc.
 They have a molecular weight less than 2000 Dalton.
 They have a ability to stabilize at high temperature .
 They are known as a synzymes enzyme mimics.

5.  XNAzymes are capable of cutting and jioning
strands of RNA in a test tube . These are used
in the treatment of various diseases like cancer
viral infections. These are not recognized by
body natural degrading enzyme as they are
extremely robust.
 Manganese dioxide (Mn3O4) ROS (reactive
oxygen species) scavenging activities have been
developed for in vivi anti-inflammation.
 Vanadium pentoxide mimics to glutathione
peroxide.

6. Hydrogen bonding and/or electrostatic binding
sites complementary to the substrate .
Catalytic group attached to the model.
Rigid structure model.
Water soluable and catalytically active under
physiological conditions.
Reversable , non-covalent binding with the
release slower than the binding.

7.  Tunable structure and catalytic efficiencies
similar to enzymes.
 Excellent tolerance to experimental condition.
 Purely synthetic routes for routes for their
preparation.
 High east and low stability limit the
applications of natural enzymes.
 Speeds up the reaction at a relatively high
rate.

8. Two types of approaches used to develop artificial
Enzyme.
1.Chemical approach:
 Cyclodextrins as enzyme mimics
 Cyclophane as enzyme mimics
 Calixarene as enzyme mimics
 Crown ethers as enzyme mimics
2.Biological approch:
 Direct evolution method for artificial enzyme
designing.

9.  The three most common cyclodextrins are,α-,β-
,and γ- species ,which are composed of six, seven
and eight glucopyranose units, respectively.
 Hydrophobic cavity.
 Stable and water soluable.
 Tunable(modify to change properties).
 Research on cyclodextrin started in 1930s
 Very expensive & thought to be toxic
 1970s – non toxic.

10.  Direct evaluation is a molecular biology method
to modify biocatalysts via in vitro version of
“Darwinian evolution “.
 Direct evolution provide improved enzymatic
activity, thermostability , tolerance to organic
solvent, substrate specificity, enantioselectivity
and so on.
 Gene mutaginesis
 Insertion into host
 Transformed colony
Example: Sitagliptin

11.  Gene mutagenesis
 Insertion of gene sequence into host cell
 Transformed colony plating.
 Bacteria producing mutant enzymes.
 Screening for transformed colonies.
 Evaluate by using enzymatic assays.
 More production of transformed colonies .
 Eg: SITAGLIPTIN – It is used to treat
patients with type 2 diabetes and high
blood pressure.

12.  Under this automated identification of amino acid
sequences performed that fold into a specified
three-dimensional structures.This method gas
emerged as a promising tool for engineering
enzymes.
 Conformational changes are part of the repertoire
that natural enzymes use to catalyze react ions.
Tools used:
• Path pred
• RDM patterns
• Bond-Electron matrices
• Reaction SMARTS in Rectro
• Path 2.0

13.  The covalent immobilization of one enzyme on solid
supports having large surface with given properties
(eg: hydrophilic or hydrophobic surfaces) should
provide a nano environmental surrounding the area
of the enzyme directly in contact with the support.
 Further covalent immobilization of macromolecular
polymers (hydrophilic, hydrophobic) on the same large
internal surfaces of the solid support should provide
additional nano environment surrounding the area of
immobilized enzyme molecules next to the support.
 Chemical modification of immobilized enzymes with
polyfunctional macromolecules could also be an
interesting way to greatly modified the enzyme nano
environment with minimal chemical modification of
the enzyme.

14.  Tunable structure and catalytic efficiencies similar to
natural enzymes.
 Excellent Tolerance to experimental condition.
 Purely synthetic routes for their preparation
 Lower cost .
 Pharmaceutical: Synthetic enzymes that accelerates the
formation of drugs and chemical.
 Medicine: Use of synthetic enzymes as supplements for
patients deficient in certain enzyme can be made
instead of extracting natural enzymes from other
organisms.
 Genetic: Potentially designing synthetic enzymes that
manipulate gene sequences to create genetically
modified organism or to help genealogy research.