VPB 112: General Veterinary Biochemistry (1+1)

GLYCOPROTEINS

• They are proteins containing carbohydrates. The carbohydrate chain of a glycoprotein varies in length from 1 to 15 residues and is also called as oligosaccharide.
• The chain may be branched or unbranched. In mature glycoprotein glucose is absent. Uronic acids are absent.
• The carbohydrates present in glycoproteins are

Hexoses	Mannose and galactose
Acetylhexosamine	N-Acetylglucosamine andN- Acetylgalactosamine
Pentoses	Arabinose and Xylose
Methyl pentose	L-fucose
Sialic acid	N- Acetylneuraminic acid

• Functions of glycoproteins are
  • Structural molecule e.g., collagen
  • Transport proteins. E.g., Transferrin, ceruloplasmin
  • Enzymes. E.g.alkaline phosphatase.
  • Hormones. E.g., Thyroid stimulating hormone
  • Immunologic molecule. e.g., antibodies.
  • Antifreeze Proteins. e.g., Certain plasma proteins of cold water fish.
  • Cell attachment - recognition site.