Glycoprotein

<p>Wikipedia</p>

<p>Glycoproteins are proteins which contain oligosaccharide chains (glycans) covalently attached to amino acid side-chains.</p>

<p>Glycoproteins are important for white blood cell recognition. Examples of glycoproteins in the immune system are:</p>

<ul>

<li>molecules such as antibodies (immunoglobulins), which interact directly with antigens.</li>

<li>molecules of the <em><a title="Major histocompatibility complex" href="https://en.wikipedia.org/wiki/Major_histocompatibility_complex">major histocompatibility complex</a></em> (or MHC), which are expressed on the surface of cells and interact with T cells as part of the adaptive immune response.</li>

<li>sialyl Lewis X antigen on the surface of leukocytes.</li>

</ul>

<p>H antigen of the ABO blood compatibility antigens. Other examples of glycoproteins include:</p>

<ul>

<li>gonadotropins (luteinizing hormone a follicle-stimulating hormone)</li>

<li><a title="Glycoprotein IIb/IIIa" href="https://en.wikipedia.org/wiki/Glycoprotein_IIb/IIIa">glycoprotein IIb/IIIa</a>, an integrin found on platelets that is required for normal platelet aggregation and adherence to the endothelium.</li>

<li>components of the <a title="Zona pellucida" href="https://en.wikipedia.org/wiki/Zona_pellucida">zona pellucida</a>, which surrounds the <a title="Oocyte" href="https://en.wikipedia.org/wiki/Oocyte">oocyte</a>, and is important for sperm-egg interaction.</li>

<li>structural glycoproteins, which occur in connective tissue. These help bind together the fibers, cells, and ground substance of connective tissue. They may also help components of the tissue bind to inorganic substances, such as calcium in bone.</li>

<li>Glycoprotein-41 (<a title="Gp41" href="https://en.wikipedia.org/wiki/Gp41">gp41</a>) and glycoprotein-120 (<a class="mw-redirect" title="Gp120" href="https://en.wikipedia.org/wiki/Gp120">gp120</a>) are HIV viral coat proteins.</li>

</ul>

<p>Soluble glycoproteins often show a high viscosity, for example, in egg white and blood plasma.</p>

<ul>

<li><a title="Miraculin" href="https://en.wikipedia.org/wiki/Miraculin">Miraculin</a>, is a glycoprotein extracted from <em><a title="Synsepalum dulcificum" href="https://en.wikipedia.org/wiki/Synsepalum_dulcificum">Synsepalum dulcificum</a></em> a berry which alters human tongue receptors to recognize sour foods as sweet.</li>

</ul>

<p><a class="mw-redirect" title="Variable surface glycoprotein" href="https://en.wikipedia.org/wiki/Variable_surface_glycoprotein">Variable surface glycoproteins</a> allow the sleeping sickness <em>Trypanosomaparasite</em> to escape the immune response of the host.</p>

<p>The viral spike of the human immunodeficiency virus is heavily glycosylated</p>

<p>Hormones that are glycoproteins include:</p>

<ul>

<li>Follicle-stimulating hormone</li>

<li>Luteinizing hormone</li>

<li>Thyroid-stimulating hormone</li>

<li>Human chorionic gonadotropin</li>

<li>Alpha-fetoprotein</li>

<li>Erythropoietin (EPO)</li>

</ul>

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