Amino Acid Properties

¡@Amino Acid Properties

This list is provided as a study guide to help remind you of the properties of the side chains/R-groups of the twenty amino acids which are present in newly synthesized proteins. The R-groups can be classified in many different ways, several of which are described below. You should not need to memorize the list, but should be able to predict the properties from your knowledge of the structures of the side chains and basic principles of organic chemistry. To learn more about an amino acid, to find out which amino acid a one letter code abbreviates, and to view its structure click on it!

  1. All - G, A, V, L, I, P, F, Y, W, S, T, N, Q, C, M, D, E, H, K, R
  2. Polar / hydrophilic - N, Q, S, T, K, R, H, D, E, (C, Y)*
  3. Non-polar / hydrophobic - (G), A, V, L, I, P, Y, F, W, M, C
  4. H-bonding - C, W, N, Q, S, T, Y, K, R, H, D, E
  5. Sulfur containing - C, M
  6. Charged at Neutral pH Negative / acidic - D, E, (C)
  7. Charged at Neutral pH Positive / basic - K, R, (H)
  8. Ionizable - D, E, H, C, Y, K, R
  9. Aromatic - F, W, Y, (H, but no significant UV absorption)
  10. Aliphatic - G , A, V, L, I, P
  11. Forms covalent cross-link (disulfide bond) - C
  12. Cyclic - P
  13. Hard to remember one letter code - W, Y, K, N, Q, D, E

*Note: Amino acids in parentheses have the indicated character to a limited extent.