Proteins - Serum Albumin Flashcards
Serum Albumin
This is a blood protein carrying many bioactive molecules in the blood(proteins, peptides, FA, hormones etc) in the blood, being a critical transport molecule.
What are the functions of Serum Albumin?
ROS scavenging
Transport smaller, hydrophobic molecules
Contributes 80% to osmotic swelling pressure of blood plasma
What is the synthesis pathway of Serum Albumin?
Synthesis occurs in the liver, maturing in the ER and Golgi then secretion from hepatocytes.
What is the concentration of albumin in the blood?
40g/L
What are the 2D structures of Serum Albumin?
Water-soluble, anionin globular protein with a 66.5 kDa with 585AA and 17 disulfide bonds
What is the 3D structure of the serum albumin?
11 Hydrophobic binding domains so can carry multiple FA
Three similar domains each with two domains, each with one long-alpha helix and many beta sheets.
Disulphide Bonds
These are covalent interactions between the sulfur atoms of two cysteine residues.
What amino acid residues are important for FA binding?
Tryptophan and Phenylalanine
How does fatty acid binding affect structure of Serum Albumin?
Conformational changes when FA binds hydrophobic cavity causing AA shifts forming new H-bonds and VDW interactions.
What does FA binding cause?
Increased albumin compaction due to hydrophobic interactions between FA protein hydrophobic residues.
FA tail buried within hydrophobic cavity in the protein, in tandem with head group hydrophilic interactions with polar amino acids.
Why do fatty acids require carrier molecules?
Fatty acids have high hydrophobicity.
Alpha Helicies
These are rod-like structures with inner sections of a tightly-coiled main chain and side chains extending outwards in a helical fashion.
What stabilises Alpha Helicies?
CO and NH hydrogen bonding
How is the hydrophobic cavity formed?
Orientiation of non-polar side chain towards the core.
What determines ligand-binding sites for molecules?
Conformation/Arragnement of alpha helicies.