Dehydroalanine

Structural formula
General
Surname	Dehydroalanine
other names	DHA; 2-aminopropenoic acid; 2-amino acrylic acid;
Molecular formula	C 3 H 5 NO 2
External identifiers / databases
PubChem	123991
ChemSpider	110510
DrugBank	DB02688
Wikidata	Q1183089
properties
Molar mass	87.08 g mol −1
safety instructions
GHS hazard labeling ; no classification available
GHS hazard labeling ; no classification available
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Dehydroalanine ( DHA ) is an amino acid with the systematic name 2-aminopropenic acid, which occurs naturally only in peptide bounds . It arises from the proteinogenic amino acid cysteine by splitting off hydrogen sulfide (H ₂ S). As the primary enamine, free dehydroalanine is unstable and rearranges into its tautomer 2-iminopropanoic acid.

Ammonia , amines and thiols can add to the double bond and thus cross- link the protein chains to form so-called "cross links" . For example, dehydroalanine in proteins can react with the terminal amino group of lysine to form lysinoalanine ( LAL ). This cross-linking affects the degradability of the protein in the human body.

In food quality assurance , LAL is used as a heating indicator, especially for milk . If the proportion of LAL in the sample is too high, the milk was evidently either exposed to excessively high temperatures or treated for too long during the thermal treatment ( sterilization , pasteurization, etc.).

Two enzymes with this amino acid are known: phenylalanine ammonia lyase (plants and fungi) and histidase (living beings). The antibiotics nisin and subtilin each contain two molecules of dehydroalanine. It is also found as a building block in microcystins .

Individual evidence

↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
↑ ^a ^b ^c Entry on 2-aminoacrylic acid. In: Römpp Online . Georg Thieme Verlag, accessed on October 10, 2015.
↑ ish.ch: Occurrence of lysinoalanine in milk and milk products. In: agrarforschungschweiz.ch. Retrieved October 10, 2015 .
↑ PROSITE : Phenylalanine and histidine ammonia-lyases active site .

[NV-1] This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.

[Roempp-2] Entry on 2-aminoacrylic acid. In: Römpp Online . Georg Thieme Verlag, accessed on October 10, 2015.

[3] sh.ch: Occurrence of lysinoalanine in milk and milk products. In: agrarforschungschweiz.ch. Retrieved October 10, 2015 .

[4] PROSITE : Phenylalanine and histidine ammonia-lyases active site .