Glycoprotein is a type of protein that has a carbohydrate attached. This occurs during or after protein translation through glycosylation. Glycoproteins are more hydrophilic than proteins due to sugar hydroxyl groups, allowing them to function in aqueous environments like cell membranes. They play important structural and functional roles in cells and organisms, including roles in cell signaling, immune response, hormones, and strengthening of tissues. Examples of important glycoproteins include those involved in blood clotting, cell markers, and parasites attaching to human blood cells.

1. Glycoprotein

2. •A glycoprotein is a type of protein molecule that has had a
carbohydrate attached to it.
•The process either occurs during protein translation or as a
posttranslational modification in a process called
glycosylation.
•The carbohydrate is an oligosaccharide chain (glycan) that is
covalently bonded to the polypeptide side chains of the
protein.
•Because of the -OH groups of sugars, glycoproteins are
more hydrophilic than simple proteins.
•This means glycoproteins are more attracted to water than
ordinary proteins.

3. •Glycoproteins function in the structure, reproduction,
immune system, hormones, and protection of cells and
organisms.
•Glycoproteins are found on the surface of the lipid bilayer
of cell membranes.
•Their hydrophilic nature allows them to function in the
aqueous environment, where they act in cell-cell
recognition and binding of other molecules.
•Cell surface glycoproteins are also important for cross-
linking cells and proteins (e.g., collagen) to add strength and
stability to a tissue. Glycoproteins in plant cells are what
allow plants to stand upright against the force of gravity.

4. •Glycosylated proteins are not just critical for intercellular
communication.
• They also help organ systems communicate with each
other.
•Glycoproteins are found in brain gray matter, where they
work together with axons and synaptosomes.
•Hormones may be glycoproteins. Examples include human
chorionic gonadotropin (HCG) and erythropoietin (EPO).
•Blood clotting depends on the glycoproteins prothrombin,
thrombin, and fibrinogen.

5. •Cell markers may be glycoproteins. The MN blood groups
are due to two polymorphic forms of the glycoprotein
glycophorin A. The two forms differ only by two amino acid
residues, yet that is enough to cause problems for persons
receiving an organ donated by someone with a different
blood group. The Major Histocompatibility Complex (MHC)
and H antigen of the ABO blood group are distinguished by
glycosylated proteins.
•Glycophorin A is also important because it's the attachment
site for Plasmodium falciparum, a human blood parasite.

6. 1. Castor
•Syn: Erandi
•Source: dried seeds of Ricinus communis
•Family: Euphorbiaceae
•Constituents: glycoprotein-lectin-ricin
•Ricin causes haemolysis if taken IV but not ingestion
•Ricin is present throughout plant, seeds contain highest %
of ricin.
•In addition to ricin, leaves, stem and seeds also contain
potassium nitrate & HCN.

7. 1. Castor
•Toxicity occurs after well masticated seeds, where whole
seeds are relatively nontoxic.
•Castor seeds contain 40% fixed oil, 1-5% ricin & 0.5-0.8%
ricinine
•Ricin is type-II ribosomal inactivating protein, mannose rich
N-linked oligosaccharide, as carbohydrate sidechain.
•Ricin suppress growth of ascites of tumour cells probably
by inhibiting protein synthesis at ribosomal level (Anti-
cancer)

8. 2. Pea
•Syn: Garden Pea, Matar
•Source: cotyledons of Pisum Sativum
•Family: Leguminosae
•Constituents: glycoprotein-Legumin, Vicilin
•Legumin: 1% neutral sugar (mannose, glucose), 0.1% amino
sugar (glucosamine)
•Vicilin: 0.3 % neutral sugar (mannose), 0.2% amino sugar
(glucosamine)

10. 2. Pea
•Pisum sativum agglutinin and
phytohaem(erythro)agglutinin were found to bind to gp120.
• They were able to inhibit fusion of HIV-infected cells with
CD4 cells by a carbohydrate-specific interaction with the
HIV-infected cells (Hansen et al. 1989).
•Plant lectins displayed anti-coronaviral activity, especially
mannose-binding lectins, in severe acute respiratory
syndrome coronavirus.
•They interfered viral attachment in early stage of replication
cycle and suppressed the growth by interacting at the end
of the infectious virus cycle (Keyaerts et al. 2007).

11. 3. Oats
•Syn:
•Source: cotyledons of Avena sativa
•Family: Poaceae
•Constituents: dry seeds 8-14% protein, albumin 5-10%,
Globulin-80%, Prolamin- 5-10%, Glutelin-5%
•Causes nitrate toxicity in Live stock
•Prolamin (Avenin)- celiac & auto immune disease (safe)
•hemagglutination

12. Avenanthramides (AVAs)
controlling the blood pressure, as they produce nitric oxide which
dilates the blood vessels