Alanine
Ala
A
Unpolar, small amino acid. Used in Alanine scanning mutagenesis.
89.1 (71.1)
Arginine
Arg
R
Charged, basic, large amino acid; pKa of sidechain = 12.5
174.2 (156.2)
Asparagine
Asn
N
Polar amide sidechain; Can deamidate to Asp at alkaline pH
132.1 (114.1)
Aspartate
Asp
D
Charged, acidic amino acid
; pKa of acid sidechain = 3.9
133.1 (115.1)
Cysteine
Cys
C
Polar, forms disulfides (Cystine); pKa of -SH group = 8.3; can also oxidize to cysteic acid
121.2 (103.2)
Glutamate
Glu
E
Charged, acidic amino acid
; pKa of acid sidechain = 4.1
147.1 (129.1)
Glutamine
Gln
Q
Polar amide sidechain; can deamidate to glutamate (not as rapid as Asn though)
146.1 (128.1)
Glycine
Gly
G
Small, flexible amino acid; found in turns due to the phi-psi angles it can assume.
75.1 (57.1)
Histidine
His
H
Polar, charged basic amino acid; pKa of sidechain = 6.0; often found in the active site of proteins as a dual function proton donor and acceptor
155.2 (137.2)
Isoleucine
Ile
I
Hydrophobic alkane sidechain
131.2 (113.2)
Leucine
Leu
L
Hydrophobic linear alkane sidechain
131.2 (113.2)
Lysine
Lys
K
Charged basic amino acid; pKa of sidechain = 10.8
146.2 (128.2)
Methionine
Met
M
Polar/unpolar sulfur-containing amino acid, initiates proteins (Coded by ATG, the start codon)
149.2 (131.2)
Phenylalanine
Phe
F
Hydrophobic aromatic amino acid, max. UV absorbance = 259 nm (molar abs = 200); fluorescence max. 282 nm (quantum yield = 0.04)
165.2 (147.2)
Proline
Pro
P
Imine ring
115.1 (97.1)
Serine
Ser
S
Polar alcohol sidechain; pKa of -OH group about 13
105.1 (87.1)
Threonine
Thr
T
Polar alcohol sidechain; pKa of -OH group about 13
119.1 (101.1)
Tryptophane
Trp
W
Hydrophobic aromatic amino acid, max. UV absorbance = 279 nm (molar abs = 5200); fluorescence max. 348 nm (quantum yield = 0.20)
204.2 (186.2)
Tyrosine
Tyr
Y
Polar aromatic amino acid, max. UV absorbance = 278 nm (molar abs = 1100); fluorescence max. 303 nm (quantum yield = 0.21); pKa of -OH group = 10.1
181.2 (163.2)
Valine
Val
V
Hydrophobic branched alkane sidechain
117.1 (99.1)