BSE
Diagram of Essential Amino Acid
Lysine
●
●
Lysine is a base
Physical properties:
Polar, positively charged
●
●
●
Highly reactive
Hydrophilic
Solubility: ^ soluble in cold water
●
●
Reactivity: 0
Flammability: 1 (may be combustible at high temps
Protein Structure
Dehydration
Hydrolysis
Stabilizing Forces
1)
Hydrophobic Interactions Non polar amino acids (leucine and phenylalanine are two examples). Weakest type of bond.
2)
Hydrogen bonds: Polar or charged amino acids (example Tyrosine). Weak interaction but stronger than the hydrophobic interaction
3)
Ionic Bonds: Charged amino acids (Lysine and Aspartic acid are examples). Opposite attract. Little stronger than hydrogen bond but weaker than the bond between polypeptides
4)
Disulfide bond: Only occurs between 2 cysteine amino acids. Forms sulfur sulfur link
(disulfide like). Strong interaction.
Bovine Spongiform Encephalopathy protein misfolding
●
●
●
●
Better known as Mad Cow Disease
Cause by an abnormal form of prions which are proteins
Slowly progressive disease that affects a cow’s central nervous system
Cattle are infected by eating food that have remains of other animals like cattle and sheep that contain the infectious prions
●
●
●
●
●
●
There are normal proteins (PrPc) and abnormal harmful prions (PrPsc). The prion is a misfolded form of PrPc.
Cells have chaperones for young proteins to help it fold correctly
Prions affect the folding of normal, healthy proteins
PrPc comes in contact with PrPsc, PrPsc affects the folding of the normal protein and causes it to fold into the harmful form of the protein
PrPsc is hydrophobic. It congregates with other PrPsc proteins forming plaques
Plaques cause neuronal cell death leaving holes that resemble a sponge.
Role of Prions in BSE
●
●
●
●
A prion is an infectious, abnormally folded protein
PrPsc is the abnormal prion in BSE
PrPc is the name of the normal protein
Prions are problems because they destroy brain tissue leading
References: BSE Control Measures. (2010, August 26). Retrieved November 17, 2014, from http://www.cdc. gov/ncidod/dvrd/bse/prevention.htm Mad cow disease: FAO recommends precautions. (2001, February 8). Retrieved November 17, 2014, from http://www.fao. org/english/newsroom/highlights/2001/010202-e.htm