Nonpolar, aliphatic amino acids

Nonpolar, aliphatic amino acids

On inside of proteins, stabilizes core of protein

Hydrophobic effect stabilizes protein structure

Aliphatic: carbon atoms form open chains, as in alkanes

Glycine (Gly, G)

nonpolar, hydrophobic

R group consists of H

Alanine (Ala, A)

nonpolar, hydrophobic

R group consists of CH3

Proline (Pro, P)

nonpolar, hydrophobic;

alpha helix breaker - rigid, causes kinks in the secondary protein structure alpha helices

Alpha amino is not free, attached in 4-C pentagon (including alpha)

Valine (Val, V)

nonpolar, hydrophobic

R group is isopropyl group

Leucine (Leu, L)

nonpolar, hydrophobic

R group is Ch2-isopropyl

Isoleucine (Ile, I)

nonpolar, hydrophobic

R group is alpha-C bonded to H-C-C3. Middle C is bonded to ethyl group.

Methionine (Met, M)

nonpolar, hydrophobic

R group is Ch2-Ch2-S-Ch3

Phenylalanine (Phe, F)

non-polar, aromatic, hydrophobic

Tyrosine (Tyr, Y)

polar aromatic, partial hydrophilic. pka = 10. IONIZABLE

R-OH <---> R-O- + H+

Tryptophan (Trp, W)

aromatic, hydrophobic

Aromatic R groups

useful for detection, absorbs UV light around 280 nm