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Peptide Tools

Sl. No. Amino acid One letter code Three letter code
1 Glycine G Gly
2 Alanine A Ala
3 Leucine L Leu
4 Methionine M Met
5 Phenylalanine F Phe
6 Tryptophan W Trp
7 Lysine K Lys
8 Glutamic acid E Glu
9 Glutamine Q Gln
10 Serine S Ser
11 proline P Pro
12 Valine V Val
13 Isoleucine I Ile
14 Cysteine C Cys
15 Tyrosine Y Tyr
16 Histidine H His
17 Arginine R Arg
18 Aspargine N Asn
19 Aspartic acid D Asp
20 Threonine T Thr


Amino Acid Pka value Pka value Pka value
  Name Alpha Carboxy +Alpha Amino Side Chain
Non-polar Amino Acid Glycine 2.34 9.60  
Alanine 2.34 9.69
Valine 2.32 9.62
Leucine 2.36 9.60
Isoleucine 2.36 9.68
Methionine 2.28 9.21
Phenylalanine 1.83 9.13
Tryptophan 2.38 9.39
Proline 1.99 10.60
Polar Amino Acids Serine 2.21 9.15  
Threonine 2.63 9.10
Cysteine 1.71 10.78 8.33
Tyrosine 2.2 9.11 10.07
Asparagine 2.02 8.84  
Glutamine 2.17 9.13
Acidic Amino Acids Aspartic Acid 2.09 9.82 3.86
Glutamic Acid 2.19 9.67 4.25
Basic Amino Acids Lysine 2.18 8.95 10.79
Arginine 2.17 9.04 12.48
Histidine 1.82 9.17 6.04
1 Glycine G Gly 2 Alanine A Ala 3 Leucine L Leu 4 Methionine M Met 5 Phenylalanine F Phe 6 Tryptophan W Trp 7 Lysine K Lys 8 Glutamic acid E Glu 9 Glutamine Q Gln 10 Serine S Ser 11 proline P Pro 12 Valine V Val 13 Isoleucine I Ile 14 Cysteine C Cys 15 Tyrosine Y Tyr 16 Histidine H His 17 Arginine R Arg 18 Aspargine N Asn 19 Aspartic acid D Asp 20 Threonine T Thr