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