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L-histidine

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

EntityQ485277· pop 63· linked from 1,817 articles

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

OverviewAI-generated

L-histidine is a chemical compound with the formula C₆H₉N₃O₂. Its IUPAC name is (2S)-2-azaniumyl-3-(1H-imidazol-5-yl)propanoate. The substance has a mass of 155.069477 and a weight of 155.15. It exhibits a melting point of 287 and a pKa of 9.18.

Structural properties include an xlogp of -2.6 and a tpsa of 96.5. The molecule contains two hydrogen bond donors and three hydrogen bond acceptors, with a net charge of 0. Canonical SMILES notation is C1=C(NC=N1)CC(C(=O)O)N, while isomeric SMILES is N[C@@H](CC1=CNC=N1)C(O)=O.

The compound is associated with a PubMed query count of 61702. It is referenced by 1,817 other encyclopedia articles.

Synthesized by Vinony from 21 facts across 4 sources: Wikidata, PubChem, PubMed, Vinony graph. Generated from structured data (not the Wikipedia text) and checked against those facts — may still 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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