BGM1002/L03 Proteins In Health Flashcards
How many subunits does myoglobin consist of?
1 - tertiary structure
How many subunits does haemoglobin consist of?
4 - tertiary & quaternary structure
What is the tertiary structure of a protein?
Overall 3D shape
What are the ‘chunks’ that proteins fold into called?
Domains
How many amino acids long is a typical domain?
100-200
What is the term given to related amino acid sequences which give similar structures?
Structural homology
What is better conserved: structure or sequence?
Structure
Where is protein folding encoded?
Amino acid sequence - primary encoded
What database holds all amino acid sequences/protein structure data?
Protein Data Back (PDB)
What 2 programmes are able to predict protein structure?
ML & LLM
What can quaternary proteins bind to?
Other protein chains (homo-hetero interactions)
Small molecules (metals/cofactors)
How does myoglobin/haemoglobin bind the haem cofactor?
Porphyrin ring with iron coordinated
Globin protein coordinates iron axially
What is myoglobin?
Monomer that binds oxygen in muscle and delivers oxygen to muscle in low saturations
What is haemoglobin?
Tetramer that binds oxygen in lungs/blood and releases oxygen to tissues in low saturations
What does Hb’s oxygen affinity depend on?
Amount of blood oxygen
What other factors can affect Hb’s affinity for oxygen? (3)
Chloride ions
Bis-phosphoglycerate
Protonation state of Hb
Carbon dioxide binding
Ligand binding state
What kind of disease is Sickle Cell Anemia?
Autosomal recessive
What mutation causes sickle cell anemia?
Subsitution E6V
What causes Cystic Fibrosis?
Truncation of CFTR protein
What kind of mutation causes CF?
Missense (incomplete protein/premature stop codon)
What does CFTR stand for?
Cystic Fibrosis Transmembrane Conductance Regulator
What is Phenylketonuria (PKN)?
Loss and poor function of phenylalanine hydroxylase
What is Type 1 Diabetes?
Autoimmune disease which causes destruction of pancreatic beta cells, preventing insulin production
How does blood clotting occur?
Platelets aggregate to stop bleeding by forming a clot - clotting cascade
When does the clotting cascade occur?
In response to endothelial damage
What is haemophilia?
Poor blood clotting due to deficiency in factor VIII (A), IX (B) or low levels of factor XI (C)
What type of disorder is haemophilia?
X-linked
