Visualising Proteins

The following are a selection of protein molecules that highlight different aspects of protein structure

  • Click on the links provided to view the interactive pop up


  • Haemoglobin is a globular protein responsible for oxygen transport within red blood cells
  • It has a quaternary structure made up of four polypeptide subunits (2 alpha subunits and 2 beta subunits)
  • Each polypeptide chain is associated with a prosthetic heme group (responsible for oxygen binding)


  • Aquaporins are integral membrane proteins that form channels that allow for the passage of water molecules
  • Aquaporins form tetramers in the cell membrane, with each monomer allowing for water movement
  • The pores of the aquaporin are impermeable to charged species, thus preventing the passage of ions or solutes


  • Keratin is a fibrous protein that functions as a key structural material in hair, skin and nails
  • Keratin proteins form long twisted strands that may interconnect via disulphide bridges
  • Tougher keratin fibres found in hair and nails have more disulphide bridges than more elastic keratin fibres found in skin

Green Fluorescent Protein

  • Green fluorescent protein is a fluorophore produced by jellyfish (and commonly used in recombinant DNA experiments)
  • The fluorescing chromophore is attached to a central alpha helix, which is surrounded by 11 beta strands forming a barrel
  • The tightly packed beta barrel excludes solvent molecules and functions to protect the chromophore from quenching by water

Examples of Protein Structures

protein structures