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L-histidine

File:L-Histidin_-_L-Histidine.svg · Wikimedia Commons · See Wikimedia Commons

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L-histidine

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Also known as L-His, (S)-4-(2-Amino-2-carboxyethyl)imidazole, (S)-a-Amino-1H-imidazole-4-propanoic acid, (S)-alpha-amino-1H-Imidazole-4-propanoic acid, (S)-alpha-Amino-1H-imidazole-4-propionic acid, (S)-α-amino-1H-Imidazole-4-propanoic acid, H, His

thumb|Histidine ball and stick model spinning Histidine or histidin (symbol His or H) is an essential amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated –NH3+ form under biological conditions), a carboxylic acid group (which is in the deprotonated –COO− form under biological conditions), and an imidazole side chain (which is partially protonated), classifying it as a positively charged amino acid at physiological pH. Initially thought essential only for infants, it has now been shown in longer-term studies to be essential for adult

AI overview

L-histidine is an essential amino acid, meaning your body needs it to build proteins but cannot produce it on its own, so you must obtain it from food. It has a unique chemical structure with a positively charged side chain that allows it to play important roles in protein function, and while once thought necessary only for infants, research has shown it remains essential for adults as well.

AI-generated from the Wikipedia summary — may contain errors.

Chemical data

Formula
C6H9N3O2
Molecular weight
155.15 g/mol
IUPAC name
(2S)-2-azaniumyl-3-(1H-imidazol-5-yl)propanoate
SMILES
C1=C(NC=N1)C[C@@H](C(=O)[O-])[NH3+]
InChIKey
HNDVDQJCIGZPNO-YFKPBYRVSA-N
XLogP
-2.6
Polar surface area
96.5 Ų
H-bond donors
2
H-bond acceptors
3
Formal charge
0

via PubChem

Research

61,702 papers

via PubMed

~13 min read

Encyclopedic overview

12 sections
Contents
  • Properties of the imidazole side chain
  • Ligand
  • Metabolism
  • Biosynthesis
  • Regulation of biosynthesis
  • Degradation
  • Conversion to other biologically active amines
  • Requirements
  • Medical uses
  • See also
  • References
  • External links

thumb|Histidine ball and stick model spinning Histidine or histidin (symbol His or H) is an essential amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated –NH3+ form under biological conditions), a carboxylic acid group (which is in the deprotonated –COO− form under biological conditions), and an imidazole side chain (which is partially protonated), classifying it as a positively charged amino acid at physiological pH. Initially thought essential only for infants, it has now been shown in longer-term studies to be essential for adults also. It is encoded by the codons CAU and CAC.

Histidine was first isolated by Albrecht Kossel and Sven Gustaf Hedin in 1896. The name stems from its discovery in tissue, from histós "tissue". It is also a precursor to histamine, a vital inflammatory agent in immune responses. The acyl radical is histidyl.

Excerpted from Wikipedia’s “L-histidine” article, available under the CC BY-SA 4.0 licence.

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