protein folding and function

protein folding and function

1. structure

   • primary
     • covalent peptide bonds
     • linear sequence of aa
   • secondary
     • B pleated sheet a helix
       • antiparallel 0.35 nm between aa
       • 3.6 aa/ turn 0.54nm pitch
     • pro & gly helix breakers
   • tertiary
     • 3D arrangement
     • covalent, ionic, H bonds, Van de Waal, hydrophobic
   • quaternary
     • more than one pp subunit

2. conformation

   • globular
     • catalysis, regulation
     • compact
     • haemoglobin
     • motif - folding pattern with ore than 1 element of secondary
     • domain - distinct folded shape
   • fibrous
     • support , shape, protection
     • long strands
     • collagen
   • info to fold found in primary sequence, some need chaperone

3. denaturation

   • heat - increased kinetic energy
   • pH - alters ionaisation
   • solvents - disrupt hydrophobic
   • misfolding can cause disease
     • amyloid fibres
       • misfolded, insoluble form of protein