Amino acids

Glycine, Gly, G

has conformational freedom due to small side chain. can be found in both hydrophobic and hydrophilic environments

Alanine, A, Ala

nonpolar, involved in hydrophobic interaction

Valine, V, Val

nonpolar, beta-branching decreases conformational freedom

Leucine, L, Leu

nonpolar, no beta-branching

Isoleucine, I, Ile

nonpolar, beta-branching decreases conformational freedom

Methionine, M, Met

nonpolar, thioether group can be oxidized to sulfoxide

Proline, P, Pro

nonpolar. amino acid with least conformational freedom due to ring

Tryptophan, W, Trp

aromatic, hydrophobic, can participate in H-bonding. indole side chain is bulky

Tyrosine, Y, Tyr

hydrophobic, aromatic, H-bonding possible. phenol group is bulky but not as much as Trp

Phenylalanine, F, PHe

hydrophobic, aromatic, relatively bulky

Serine, S, Ser

polar, uncharged, H-bonding possible

Threonine, T, Thr

polar, uncharged, H-bonding possible. Beta-branching restricts conformational freedom

Asparagine, N, Asn

polar, uncharged, H-bonding possible

Glutamine, Q, Gln

polar, uncharged, H-bonding possible

Cysteine, C, Cys

polar, uncharged

Lysine, K, Lys

charged, can be involved in electrostatic interactions. good nucleophile when amino group is deprotonated

Arginine, R, Arg

charged, can be involved in H-bonding and electrostatic interactions. Guanidino group is not nucleophilic

Histidine, H, His

charged, can be involved in H-bonding and electrostatic interactions. Involved in many catalytic mechanisms

Aspartic acid, Asp, D

charged, can be involved in H-bonding and electrostatic interactions. Can be involved in salt bridge

Glutamic acid, E, Glu

charged, same as aspartic acid but additional methylene group increases pKa