Page 70 - Color Atlas of Biochemistry

Amino Acids 61

A. The proteinogenic amino acids

Aliphatic Sulfur-containing
Glycine Alanine Valine Leucine Isoleucine Cysteine Methionine
(Gly, G) (Ala, A) (Val, V) (Leu, L) (Ile, I) (Cys, C) (Met, M)

H CH 3 H C CH CH 2 H C C H CH 2 CH 2
3
3
CH 3 H C CH CH 2 SH CH 2
3
8.3
CH 3 CH 3 S
pKa value CH 3
Polarity

–2.4 –1.9 –2.0 –2.3 –2.2 –1.2 –1.5

Aromatic Cyclic Neutral
Phenylalanine Tyrosine Tryptophan Proline Serine Threonine
(Phe, F) (Tyr, Y) (Trp, W) (Pro, P) (Ser, S) (Thr, T)

CH 2 CH 2 CH 2 COO CH 2 H C C H
3
CH OH OH
HN CH 2
N H C CH 2
2
H
Indole ring Pyrrolidine ring
OH
10.1

+0.8 +6.1 +5.9 +6.0 +5.1 +4.9
Essential amino acids Chiral center

Neutral Acidic Basic
Asparagine Glutamine Aspartic acid Glutamic acid Histidine Lysine Arginine
(Asn,N) (Gln, Q) (Asp, D) (Glu, E) (His, H) (Lys,K) (Arg, R)

CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2

CONH 2 CH 2 COO CH 2 CH 2 CH 2
4.0 HN CH
CONH 2 COO HC N CH 2 CH 2
4.3
6.0 CH NH
Imidazole ring 2
NH 3 C
10.8 H N NH 2
2
12.5
+9.7 +9.4 +11.0 +10.2 +10.3 +15.0 +20.0

Koolman, Color Atlas of Biochemistry, 2nd edition © 2005 Thieme
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