Covalent and non Covalent interaction in Macromolecules,types of bonding in macromolecules

1. PRESENTED TO: PRESENTED BY:
PROFESSOR OJASWI SINHA ABDUR RAHAMAN
ASHWANI KUMAR SINGH
ASHISH VERMA
RAHUL TRIPATHI
RISHABH CHAURASIYA

2. MACROMOLECULES INTERACTIONS

3. 1.COVALENT INTERACTION
COVALENT BOND:
• A covalent bond is a chemical bond that involves
the sharing of electron pairs between atoms.
• This electron pair is known as shared pairs or
bonding electron, and the stable balance of a
attractive and repulsive force between atoms,
when they share electron is called covcalent
bonding.
• TYPES OF COVALENT BOND :
• A. Polar- e.g.-A water molecule, abbreviated as
H2O, is an example of a polar covalent bond
• B. Non-Polar- e.g.- peptide bond

4. BIOLOGICAL SIGNIFICANCE OF COVALENT
BOND :
1. Covalent bonds are strong enough to held
macromoleculers chain together to preserve the
sequence of subunits for long period of time.
2. One kind of non-polar covalent bond is very
siginificant in macromolecules is called peptide
bond.
3. A peptide bond joins together chains of amino
acids,which involves in construction of DNA.
4. glycosidic bond (glycosidic link) The type of
chemical linkage between the monosaccharide
units of disaccharides, oligosaccharides, and
polysaccharides, which is formed by the
removal of a molecule of water.

5. COVALENT DRUGS
• Covalent drugs have made a major impact on
human health and have been highly successful
drugs for the pharmaceutical industry. These
inhibitors react with their target proteins to form
a covalent complex in which the protein has
lost its function. The majority of these
successful drugs, which include
penicillin,omeprazole,and aspirin.
• Vigabatrin is an irreversible suicide inhibitor
of gamma-aminobutyric acid
transaminase (GABA-T), the enzyme
responsible for the catabolism of GABA, which
increases the level of GABA in the brain also
comes under this category.

6. 2.NON-COVALENT INTERACTIONS
• Hydrophobic Effect
Relese of water molecule from structured solvation
layer around the molecule as protein folds
increased the net entropy.
• Hydrogen Bond
Intraction of N-H and C=O of peptide bond leads to
local regular structures such as α-helix and β-
sheets.
• London Dispersion
Medium range weak attraction between all atoms
contributes significantily to the stablity in the interior
protein.
• Electrostatic Interactions
Long-range strong interactions between
permanently charged groups.

7. BIOCHEMICAL SIGNIFICANCE OF VAN
DER WAALS INTERACTIONS

8. HYDROPHOBIC EFFECT

9. SIGNIFICACE OF NON-COVALENT
INTERACTION
1. In aqueous environment each non-covalent bond is
30to300 times weaker than the typical covalent bond.
2. ​Unlike a single covalent bond non-covalent interactions
are too weak to withstand the thermal motions that
tends to pull molecules apart, and large number of non-
covalent bonds are needed to hold two molecular
surface together.
3. ​large number of non- covalent bond can form between
two surface only when large number of atoms on the
surface are precisely matched to each other, which
accounts for the specificity of biological recognition,
such as occur in between enzyme and substrate.

10. NON-COVALENT DRUGS
• Reversible inhibitors bind non-covalently to
enzymes.
• There are three kinds of reversible
inhibitors: competitive, noncompetitive, and
uncompetitive inhibitors.
• Few examples of Reversible inhibitors:
• Acetylcholinesterase inhbitors:- Often
abbreviated AChEI or anti-cholinesterase it is a
chemical that inhibits the enzyme
Acetylcholinesterase from breaking down
acetylcholine.Common Drug- galantamine.
• Monoamine oxidase inhibitors:- Monoamine
oxidase inhibitors (MAO inhibitors) inhibit one or
both forms of the enzyme monoamine oxidase
and prevent the breakdown of monoamine
oxidase neurotransmitters.

11. REFERENCES
1. ​Molecular biology of the cell, volume 1 by
Bruce Alberts.
2. ​https://en.wikipedia.org/wiki/Non-
covalent_interactions
3.
http://www.ncbi.nlm.nih.gov/books/NBK2
1726/
4.
http://www.imsc.res.in/~sitabhra/teachin
g/cmp03/class4.html