Flashcards in lecture 17 - red blood cells and plasma proteins Deck (27):
albumin knowledge critical for...
drug design. must bind drug to "drive" it around the body
each make antibodies specific to an antigen and make membrane-bound versions, specific to the same antigen
order the following from smallest to largest (#AA)
- serum albumin
- lysozyme ~129 amino acids
- haemoglobin ~574 amino acids
- serum albumin ~585 amino acids
- immunoglobulin ~1294 amino acids
serum albumin concentration
Concentration of 35mg/mL in serum. Main component of plasma proteins.
structure of antibody
- 2 heavy amino acid chains, 2 light amino acid chains
- built from 12 immunoglobulin (IgG) domains
- chains held by disulphide bridges (cystine responsible)
secondary structure of haemoglobin
concentration of haemoglobin in blood (overall)
where are immunoglobulins made?
B-lymphocytes (white blood cell) [aka B-cells]
how many O2 molecule carried by haemoglobin?
there are four chains each with their own heme group which binds 1 O2 molecule to the iron.
what is the same and what changes in antibodies with different specificities?
- variable region changes (different arangemnt of the emd 2 IgG domains)
- constant region stays the same
who discovered haemoglobin and how?
Max Perutz, by protein crystallography
erythrocytes made in?
reticulocytes (myeloid stem cells in the marrow)
single amino acid chain. All α-helices (secondary structure)
carrier for small insoluble molecules (lipids, hormones, steroids, man-made drugs)
diameter, shape and cellular components/contents of RBC?
- biconcave disc
- no nucleus, no organelles
- heaps and heaps of haemoglobin (340mg/mL)
how is the antigen recognised?
by its EPITOPE binding to the antigen-binding site
sickle cell anaemia vs. malaria
carrying 1 copy of the mutated gene causes resistance to malaria.
blood type determined by?
blood group antigens present on membrane of erythrocytes
role of immunoglobulin in immune system? (analogy)
prior knowledge - can bind to all sorts of bacteria/virus. millions of different binding specificities
volume of red blood cells: volume of blood. Higher in males because testosterone increases EPO = more RBC production.
lifetime of red blood cells?
sickle cell anaemia mutation cause? results?
point mutation of single nucleotide A to T in haemoglobin sequence. Results in what should be GIutamic acid, being replaced with Valine. Protein produced forms fibres which disfigure erythrocytes into the sickle shape.
concentration of immunoglobulin/antibodies in serum
- small length of amino acids folded into c-shape held by disulphide bridge
- All β-pleated sheets.
linear polymers of amino acids joined by peptide bonds
structure of haemoglobin
- 2 amino acid sequences (α and β not secondary structures)
- 4 subunits (ααββ)
- 4 heme groups (1 per chain)
- Alpha helical secondary structure