BIOLOGICAL ASSEMBLY OR COMPLEXES

Rabeea Siddique Roll#11 8th semester

Institute of Biotechnology and Genetic Engineering, the University of Agriculture Peshawar, Pakistan

CONTENTS:TYPES OF BIOLOGICAL ASSEMBLIESINTRAMOLECULAR BIOLOGICAL ASSEMBLIES

1) GLYCOPROTEINSBIOLOGICAL ROLES OF GLYCOPROTEINSNANOTECHNOLOGY AND GLYCOPROTEINS

2) LIPOPROTEINSBIOLOGICAL ROLES OF LIPOPROTEINSSTRUCTURE & FUNCTION

3) GLYCOLIPIDSBIOLOGICAL ROLES OF GLYCOPROTEINSSTRUCTURE & FUNCTION

MOLECULAR SELF-ASSEMBLY• It  is the process by which molecules adopt a defined arrangement without

guidance or management from an outside source.• There are two types of self-assembly • Intramolecular self-assembly • Intermolecular self-assembly • Commonly, the term molecular self-assembly refers to intermolecular self-

assembly, while the intramolecular analog is more commonly called folding.• Assembly of molecules have non-covalent interactions (e.g., H-bonding,

metal coordination, hydrophoboic forces, van der walls forces/interactions, or electrostatic) as well as electromagnetic interactions.

MOLECULAR NANOTECHNOLOGY

• In the speculative vision of molecular nanotechnology, microchips of the future might be made by molecular self-assembly.

• Advantage to constructing nanostructure using molecular self-assembly for biological materials is that they will degrade back into individual molecules that can be broken down by the body.

• DNA nanotechnology is an area of current research that uses the bottom-up, self-assembly approach for nanotechnological goals.

• These DNA structures have also been used as templates in the assembly of other molecules such as gold nanoparticles and streptavidin proteins.

GLYCOPROTEINS

GLYCOPROTEINS IN NANOBIOTECHNOLOGY

• The use of nanomaterials has enhanced sensitivity and specificity of glycopeptides isolation and detection in complex biological fluids, which are critical for disease diagnosis and monitoring.

• Nanoparticles are most widely used nanomaterial to assemble chips for biomolecule enrichment because:

• Nanoparticles can be synthesized with various size and morphologies; they can be modified and diversified by numerous reagents for specific uses and exhibit unique optical and electrochemical features.

FUNCTION

• Glycoproteins play a crucial part in cell-cell recognition, and have important roles in protection and the immune response, reproduction, structural integrity and cell adhesion.

• cell-cell adhesion is the basis for the development of functional tissues in the body. The interactions between cells is mediated by the glycoproteins on those cell's surfaces.

• Many immunoglobulins are actually glycoproteins . B and T-cells contain surface glycoproteins that attract bacteria to these sites and bind them.

• They act as receptors on cell surfaces that bring other cells and proteins (collagen) together giving strength and support to a matrix.

CONT.• Carriers: glycoproteins can bind to vitamins, hormones, cations, and

other substances.• Inhibitors: many glycoproteins in blood plasma have shown anti-

proteolytic activity. • Defense: in beetles the shell is made of glycoproteins that provides

protection against attack by bacteria and fungi .• Freezing-point depression: glycoproteins were found in the sera of

Antarctic fishes to decrease the freezing point due to their apparent interaction with water.

• human sweat glands secrete glycoproteins which protect the skin from the other excretory products that could harm the skin.

LIPOPROTEINS

LIPOPROTEINS

• Lipoprotiens are globular micelle-like particles that

consist of non-polar core of triacylglycerols and

cholestrol esters

• Surrounded by an amphiphilic coating of proteins,

phospholipids and cholestrol.

• Hydrophobic part of the lipoproteins is called as the “tail” and it doesn’t have the affinity towards water; and thus stay in the core of the bilayer.

• Hydrophilic part of the phospholipid bilayer is called as the “head”, and it has greater affinity for water molecule because of its polar nature.

• The lipid bilayer arranges itself in such a manner that the tail lies inside and the heads float outwards.

CLASSIFICATION OF LIPOPROTEINS

Lipoproteins have 5 classes which vary in their physiological functions and composition.

They are namely:• Chylomicrons • Very low density lipoproteins (VLDL)• Intermediate density lipoproteins(IDL)• Low density lipoproteins (LDL)• High density lipoproteins(HDL)

APOLIPOPROTEINS

• The protein entity that coats the lipoprotiens are called as “apolipoproteins or apoproteins”.

• Human lipoproteins have at least 9 types of apolipoproteins distributed throughout in different amounts.

LIPIDS ARE TRANSPORTED AS LIPOPROTIENS

• The fatty acid product of lipid digestion that are absorbed

by the intestinal mucosa to make their way to other tissues

for catabolism or storage.

• But because they are sparingly soluble in aqueous

solution, lipids are transported by circulation in complex

with proteins.

MEDICINAL VALUE

• The recent report on dengue virus, the capsid protein and very low

density (VLD) lipoprotein relationship is identified.

• It is hypothesised that lipoviroparticles took parts in DENV life

cycle.

• By finding the interrelationship between dengue virus capsid

protein and lipoprotein it can be cured in future.

GLYCOLIPIDS

• Glycolipids  are lipids with a  carbohydrate chain covalently attached and

exposed on the outer surface of the cell.

• They are located in the outer leaflet of the plasma membrane, where they

interact with the extracellular environment

• They are essential components of all membranes in the body, but they are

found in greatest amounts in nerve tissue.

• The carbohydrate structure of the glycolipid is controlled by the glycosyltransferases that add the lipids and glycosylhydrolases that modify the glycan after addition.

ROLE OF GLYCOLIPIDS:

• Glycolipids play major role in humans in the contribution to blood type. There are four main blood types: A, B, AB and O, and this variation is because of different glycolipids present on the surface of red blood cells (erythrocytes).

• They provide stability for the cell and help cells join to other cells, acts as a recognition site for specific chemicals as well as helping to maintain the stability of the membrane and attaching cells to one another to form tissues.

• They play a role in the regulation of cellular interactions (for example, adhesion and recognition), growth, and development.

CONCLUSION

• The use of nanomaterials with various morphologies and characteristics (nanoparticles, mesoporous materials, nanosheets, nanotubes, etc.) has enabled enhanced sensitivity and specificity of molecular complexes.

• It provides better understanding of the structure, function, relationships of biological complexes and open new avenues for prevention of infectious diseases.

THANKS