Plasma Proteins

Plasma Proteins

1. Categories

   • Albunin
   • Immune proteins
   • Haemostatic proteins (clotting)
   • Binding proteins
   • ECM (extracellular matrix) proteins
   • Miscallaneous proteins
   • Lipoproteins

2. Origins

   • Liver = majority of different proteins
     • Liver is also the sire for the destruction and recycling of proteins
   • Lymphocytes = immunoglobulins
   • Fibroplasts and Epilethelial cells = ECM proteins and proteases
   • Many other cells = many other proteins

3. General actions of blood proteins

   • Osmotic balance
     • Colloid osmotic pressure of total blood pressure is 25mmHg (80% is due to Albunin)
       • Which is essential for maintenance of cell volume and interstitial fluid volume
   • Buffering
     • Proteins provide 15% of buffering capacity in the blood
   • Transport
     • Increases the carrying capacity and thus concentration of hormones, nutrients, metabolites, drugs in the blood. This is especially important for non-polar molecules
     • Binding to a large molecule give protection and extends the half life.
   • Cellular Uptake
     • Some metabolites need a specific protein to facilitate uptake into cells

4. Albunin

   • Makes up 50% of total blood protein
   • High polarity = high water soluble
   • Made and metabolised in liver
   • Functions
     • pH balance
     • Osmotic balance
     • Binding