Glycoproteins are proteins that contain oligosaccharide chains covalently attached to polypeptide side chains through a process known as glycosylation. There are two main types of glycoproteins: N-linked glycoproteins where sugars are attached to nitrogen on asparagine residues, and O-linked glycoproteins where sugars are attached to oxygen on serine or threonine residues. Glycoproteins play important roles as integral membrane proteins, in cell-cell interactions, stimulating coagulation, and as enzymes, receptors, and proteins involved in homeostasis. Examples include mucins in mucus which have water-holding capacity and resistance to digestion, and antibodies and MHC proteins which interact with antigens and T

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2. GLYCOPROTEINS

3. Introduction of Glycoproteins :
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When carbohydrates are attached to a
protein molecule, glycoproteins are
formed.
Carbohydrate :
Carbohydrates can
be defined chemically as neutral
compounds of carbon, hydrogen and
oxygen. Carbohydrates come in
simple forms such as sugars and in
complex forms such as starches and
fibers.

4. Protein :
Protein is defined as a substance that has
amino acids, compounds and
carbon, hydrogen, oxygen, nitrogen and sulfur
and is found in many foods
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5. Glycoproteins :
Glycoproteins are proteins that contain
oligosaccharide chains (glycans)
covalently attached to polypeptide
side chains. The carbohydrate is
attached to the protein in a
cotransnational or posttranslational
modification. This process is known as
glycosylation .
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6. Structure of Glycoprotein :
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7. Types
of
Glycoproteins:
 N-Linked Glycoprotein:
Such glycoproteins in which N-linked glycosylation
is done are known as N-linked glycoprotein. In N-
glycosylation, sugars are attached to nitrogen, typically
on the amide side-chain of asparagine.
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 O-Linked Glycoprotein:
Such glycoproteins in which O-Linked glycosylation
is done are known as O-linked glycoprotein. In O-
glycosylation, sugars are attached to oxygen, typically
on serine or threonine but also on non-canonical amino
acids such as hydroxylysine & hydroxyproline.

8. Importance
of
Glycoproteins:
 Glycoproteins are often important integral
membrane proteins where they play a role in
cell-cell interactions.
 Glycoproteins are important for white blood
cell recognition, especially in mammals.
 Glycoproteins also help stimulate the process
of coagulations of platelets to blood clot when
you get cut.
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9. Functions
of
Glycoproteins:
 Enzymes:
Various glycoproteins functions as enzymes.
For example: Alkaline phosphate, Palatin etc.
 Antifreeze Proteins:
Certain plasma proteins of cold water fish functions
as antifreeze protein.
 Receptor:
Various proteins are involved in hormone and drug
action.
 Homeostasis:
Glycoproteins are also present on the surface
membranes of platelets which help in homeostasis.
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10. Examples of Glycoproteins:
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 One example of glycoproteins found in the body is mucins, which are
secreted in the mucus of the respiratory and
digestive tracts. The sugars when attached to mucins give them considerable
water-holding capacity and also make them
resistant to proteolysis by digestive enzymes.
 Examples of glycoproteins in the immune system are:
i- molecules such as antibodies (immunoglobulins), which interact
directly with antigens.
ii- molecules of the major histocompatibility complex (or MHC), which are
expressed on the surface of cells and interact with T cells as part of the
adaptive immune response.

11. Thank you
Todays tip
“Take an egg daily which is
help to boost up your body”
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