Plasma proteins and hemoglobin Flashcards
1
Q
Describe the 6 features of serum albumin
A
- Synthesized in liver
- High negative charge prevents excretion in the urine
- Maintains oncotic pressure (burn treatment)
- 11 pockets acts as carrier protein
- Antioxidant
- Transports NO
2
Q
Alpha-1 antitrypsin (serpine, also Alpha-1 antichymotrypsin)
A
- Serine protease inhibitor that has protective role in inflammation.
- Inactivation by cigarette smoke leads to increased elastase activity that contributes to emphysema and COPD
3
Q
Alpha-1 acid glycoprotein
A
- Alpha-1 globin
- Carries basic or lipophilic compounds
4
Q
Serum amyloid A
A
- Alpha-1 globin
- Part of HDL secreted by liver in response to inflammatory cytokines–> recruits immune cells
5
Q
Lipoprotein
A
- Alpha-1 globin
- Part of HDL and LDL
6
Q
Name the alpa-2 globins
A
- Haptoglobin- Transports iron to spleen
- Major urinary protein
- Alpa-2 macroglobin- Protease inactivator
- Alpha-2 antiplasmin
- Ceruloplasmin- Transports copper
- Thyroxine binding protein
- Protein C- inactivates coagulation
- Angiotensin- When proteolysed by ACE causes vasoconstriction
7
Q
Proteins associated with endothelial disfunction
A
- I-CAM-1, V-CAM-1, vWF
8
Q
Proteins associated with Inflammation
A
- CRP, IL-6 and 1B, TNF
9
Q
Proteins associated with pro-coagulation
A
- PAI-1, Fibrinogen, P selectin
10
Q
How do O2 and CO2 bind to hemoglobin?
A
- O2 binds to iron
- CO2 bind to amino terminus of globin
11
Q
Describe cooperative O2 binding
A
- Electrostatic repulsion between His and porphyrin results in non-planar structure
- First O2 binding results in relaxation of the porphyrin structure and a planar structure allowing further binding
12
Q
How does protonation effect hemoglobin?
A
- Protonation induces deoxyhemoglobin
- CO2 from tissues along with anaerobic conditions (LDH) induces deoxy hemoglobin and O2 release to the tissues.
- BPG synthesis from shunt of glycolytic intermediates induces deoxy hemoglobin and O2 release in hypoxic conditions.
13
Q
Describe EPO function and regulation
A
- Cytokine that binds to receptor on RBC progenitor cells to prevent apoptosis
- Produced in renal capillaries, production increased under hypoxic conditions.
- Cleaved by constitutively produced hypoxia inducing factor (HIF)
- HIF is hydroxylated and degraded in the presence of O2.
14
Q
Where does heme biosynthesis occur?
A
- Occurs both in the mitochondria and in the cytoplasm
- ALAS and ferrochelatase in the mitochondria
- ALAD in the cytoplasm
15
Q
How does sickle cell affect RBC?
A
- Mutation in the 6th position glutamic acid to valine
- Val6 is exposed in deoxy hemoglobin form
- Exposure promotes association with alpha chain and induces hemoglobin polymerization which causes sickling.
