Proteins And Disease Flashcards
Sickle cell anemia occurs when someone has both copies of mutant Hb gene. WHAT IS THE MUTATION?
E to V mutation
Glutamate to valine mutation
On BETA subunit
Explain what happens in sickle cell when oxygen is released from haemoglobin(deoxy)
The beta subunit with the mutation forms a long chain
This changes the shape of red blood cells or sometimes breaks them
Blocks blood vessels
= symptoms
What is the long chain called that beta subunit forms in sickle cell disease
Oligomers
What do individuals have when they only have 1 gene mutant for sickle cell
Resistance to malaria
Why does valine mutation aggregate with other subunits?
Valine is hydrophobic so forms pockets which stick many subunits together
How can proteins propagate disease?
When 2 beta sheets stick together with exposed hydrogen bonds
= aggregation
= misfolded PRION PROTEIN TRANSFORMATION
What is a prion protein?
Misfolded proteins which can pass on the misfolding shape causing diseases like Alzheimer’s
Name 3 diseases that are caused by proteins missing
Haemophilia- factor VIII missing
Cancer - no tumor suppressor genes
Diabetes - destruction of insulin cells
Explain the disease haemophilia with the cascade involved in blood clotting
The extrinsic pathway is where many factor proteins will modify the next one until thrombin and fibrin is produced
VIII is missing which is a factor protein in the cascade; this means no thrombin or fibrin produced = bleed out
Which protein gets broken down in cystic fibrosis due to its mutation
CFTR protein
The CFTR protein sits on the lining of the lungs. What is its role to stop the build of mucus
It controls chloride transport into membrane
What and where is the mutation in the CFTR protein in cystic fibrosis which means it’s degraded
The PHE amino acid is deleted in one of the NBDs (nucleotide binding domain)
The structure change causes it to degrade
Insulin is a small protein hormone lowering glucose conc
Type 1 diabetes means that the producing cells are attacked so they need injections.
What does insulin form when concentrated (in injection)
Insulin hexamers - bound with a cation
These can’t be used as supply they need to dissociate into monomers
What have scientists produced to stop insulin hexamers forming replaced with monomers for insulin use
Artificial mutations from
PRO(proline) —— aspartate ASP
Proline stuck to other monomers due to it being hydrophobic
Aspartate = negative charge = soluble to dissociate
