这个标准的蛋白氨基酸列表详细说明了活细胞在蛋白质中使用的20种标准氨基酸的化学结构和性质。
内容
1.结构
2.化学性质
2.1.一般化学性质
2.2.侧链性质
2.3.基因表达和生物化学
1.结构
L-Alanine
(Ala/A)
L-Arginine
(Arg/R)
L-Asparagine
(Asn/N)
L-Aspartic acid
(Asp/D)
L-Cysteine
(Cys/C)
L-Glutamic acid
(Glu/E)
L-Glutamine
(Gln/Q)
Glycine
(Gly/G)
L-Histidine
(His/H)
L-Isoleucine
(Ile/I)
L-Leucine
(Leu/L)
L-Lysine
(Lys/K)
L-Methionine
(Met/M)
L-Phenylalanine
(Phe/F)
L-Proline
(Pro/P)
L-Serine
(Ser/S)
L-Threonine
(Thr/T)
L-Tryptophan
(Trp/W)
L-Tyrosine
(Tyr/Y)
L-Cysteine
(Cys/C)
20种氨基酸的结构和符号
由标准遗传密码编码蛋白质合成。
2.化学性质
下表列出了单字母符号、三字母符号和标准氨基酸侧链的化学性质。列出的质量是基于元素同位素在其自然丰度下的加权平均值。请注意,形成肽键会消除一个水分子,因此蛋白质链中氨基酸单位的质量减少了18.01524 Da。未确定氨基酸的单字母符号是x。三字母符号Asx或单字母符号B表示氨基酸是天冬酰胺或天冬氨酸;Glx或Z表示谷氨酸或谷氨酰胺;Xle或J表示亮氨酸或异亮氨酸。IUPAC/IUBMB现在也推荐Sec或U指硒代半胱氨酸,Pyl或O指吡咯赖氨酸。
2.1.一般化学性质
Acid |
Abbrev. |
Mass (Da) |
pI |
pK1 (α-COOH) |
pK2 (α-+NH3) |
|
Alanine |
A |
Ala |
89.09404 |
6.01 |
2.35 |
9.87 |
Cysteine |
C |
Cys |
121.15404 |
5.05 |
1.92 |
10.70 |
Aspartic acid |
D |
Asp |
133.10384 |
2.85 |
1.99 |
9.90 |
Glutamic acid |
E |
Glu |
147.13074 |
3.15 |
2.10 |
9.47 |
Phenylalanine |
F |
Phe |
165.19184 |
5.49 |
2.20 |
9.31 |
Glycine |
G |
Gly |
75.06714 |
6.06 |
2.35 |
9.78 |
Histidine |
H |
His |
155.15634 |
7.60 |
1.80 |
9.33 |
Isoleucine |
I |
Ile |
131.17464 |
6.05 |
2.32 |
9.76 |
Lysine |
K |
Lys |
146.18934 |
9.60 |
2.16 |
9.06 |
Leucine |
L |
Leu |
131.17464 |
6.01 |
2.33 |
9.74 |
Methionine |
M |
Met |
149.20784 |
5.74 |
2.13 |
9.28 |
Asparagine |
N |
Asn |
132.11904 |
5.41 |
2.14 |
8.72 |
Proline |
P |
Pro |
115.13194 |
6.30 |
1.95 |
10.64 |
Glutamine |
Q |
Gln |
146.14594 |
5.65 |
2.17 |
9.13 |
Arginine |
R |
Arg |
174.20274 |
10.76 |
1.82 |
8.99 |
Serine |
S |
Ser |
105.09344 |
5.68 |
2.19 |
9.21 |
Threonine |
T |
Thr |
119.12034 |
5.60 |
2.09 |
9.10 |
Selenocysteine |
U |
Sec |
169.06 |
|
|
|
Valine |
V |
Val |
117.14784 |
6.00 |
2.39 |
9.74 |
Tryptophan |
W |
Trp |
204.22844 |
5.89 |
2.46 |
9.41 |
Tyrosine |
Y |
Tyr |
181.19124 |
5.64 |
2.20 |
9.21 |
2.2.侧链性质
Acid |
Abbrev. |
Side chain |
Hydro- |
pKr |
Polar |
Charged |
Small |
Tiny |
Aromatic |
van der Waals |
|
Alanine |
A |
Ala |
-CH3 |
X |
– |
– |
– |
X |
X |
– |
volume |
Cysteine |
C |
Cys |
-CH2SH |
X |
8.18 |
– |
acidic |
X |
– |
– |
67 |
Aspartic acid |
D |
Asp |
-CH2COOH |
– |
3.90 |
X |
acidic |
X |
– |
– |
86 |
Glutamic acid |
E |
Glu |
-CH2CH2COOH |
– |
4.07 |
X |
acidic |
– |
– |
– |
91 |
Phenylalanine |
F |
Phe |
-CH2C6H5 |
X |
– |
– |
– |
– |
– |
Aromatic |
109 |
Glycine |
G |
Gly |
-H |
– |
– |
– |
– |
X |
X |
– |
135 |
Histidine |
H |
His |
-CH2-C3H3N2 |
– |
6.04 |
X |
weak basic |
– |
– |
Aromatic |
48 |
Isoleucine |
I |
Ile |
-CH(CH3)CH2CH3 |
X |
– |
– |
– |
– |
– |
Aliphatic |
118 |
Lysine |
K |
Lys |
-(CH2)4NH2 |
– |
10.54 |
X |
basic |
– |
– |
– |
124 |
Leucine |
L |
Leu |
-CH2CH(CH3)2 |
X |
– |
– |
– |
– |
– |
Aliphatic |
135 |
Methionine |
M |
Met |
-CH2CH2SCH3 |
X |
– |
– |
– |
– |
– |
– |
124 |
Asparagine |
N |
Asn |
-CH2CONH2 |
– |
– |
X |
– |
X |
– |
– |
124 |
Proline |
P |
Pro |
-CH2CH2CH2- |
X |
– |
– |
– |
X |
– |
– |
96 |
Glutamine |
Q |
Gln |
-CH2CH2CONH2 |
– |
– |
X |
– |
– |
– |
– |
90 |
Arginine |
R |
Arg |
-(CH2)3NH-C(NH)NH2 |
– |
12.48 |
X |
basic |
– |
– |
– |
114 |
Serine |
S |
Ser |
-CH2OH |
– |
– |
X |
– |
X |
X |
– |
148 |
Threonine |
T |
Thr |
-CH(OH)CH3 |
– |
– |
X |
weak acidic |
X |
– |
– |
73 |
Selenocysteine |
U |
Sec |
-CH2SeH |
X |
5.73 |
– |
– |
X |
– |
– |
93 |
Valine |
V |
Val |
-CH(CH3)2 |
X |
– |
– |
– |
X |
– |
Aliphatic |
|
Tryptophan |
W |
Trp |
-CH2C8H6N |
X |
– |
– |
– |
– |
– |
Aromatic |
105 |
Tyrosine |
Y |
Tyr |
-CH2-C6H4OH |
X |
|
X |
– |
– |
– |
Aromatic |
163
|
注意:当氨基酸在蛋白质内部时,氨基酸的pKa值通常略有不同。在这种情况下,蛋白质pKa计算有时用于计算氨基酸pKa值的变化。
2.3.基因表达和生物化学
Amino Acid |
Abbrev. |
Codon (s) |
Occurrence in proteins (%) |
Essential in humans |
|
Alanine |
A |
Ala |
GCU, GCC, GCA, GCG |
7.8 |
– |
Cysteine |
C |
Cys |
UGU, UGC |
1.9 |
– |
Aspartic acid |
D |
Asp |
GAU, GAC |
5.3 |
– |
Glutamate |
E |
Glu |
GAA, GAG |
6.3 |
– |
Phenylalanine |
F |
Phe |
UUU, UUC |
3.9 |
X |
Glycine |
G |
Gly |
GGU, GGC, GGA, GGG |
7.2 |
– |
Histidine |
H |
His |
CAU, CAC |
2.3 |
– |
Isoleucine |
I |
Ile |
AUU, AUC, AUA |
5.3 |
X |
Lysine |
K |
Lys |
AAA, AAG |
5.9 |
X |
Leucine |
L |
Leu |
UUA, UUG, CUU, CUC, CUA, CUG |
9.1 |
X |
Methionine |
M |
Met |
AUG |
2.3 |
X |
Asparagine |
N |
Asn |
AAU, AAC |
4.3 |
– |
Proline |
P |
Pro |
CCU, CCC, CCA, CCG |
5.2 |
– |
Glutamine |
Q |
Gln |
CAA, CAG |
4.2 |
– |
Arginine |
R |
Arg |
CGU, CGC, CGA, CGG, AGA, AGG |
5.1 |
– |
Serine |
S |
Ser |
UCU, UCC, UCA, UCG, AGU, AGC |
6.8 |
– |
Threonine |
T |
Thr |
ACU, ACC, ACA, ACG |
5.9 |
X |
Selenocysteine |
U |
Sec |
UGA |
|
– |
Valine |
V |
Val |
GUU, GUC, GUA, GUG |
6.6 |
X |
Tryptophan |
W |
Trp |
UGG |
1.4 |
X |
Tyrosine |
Y |
Tyr |
UAU, UAC |
3.2 |
– |
Stop codon |
– |
Term |
UAA, UAG, UGA |
– |
– |
注意:终止密码子不是一种氨基酸,但为了完整起见包括在内。