O-methylisourea can react with the α-amino group of lysine: Implications for the analysis of reactive lysine

Tetske G. Hulshof, Shane M. Rutherfurd, Stefano Sforza, Paul Bikker, Thomas van der Poel, Wouter H. Hendriks

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

The specificity of O-methylisourea (OMIU) to bind to the ε-amino group of Lys, an important supposition for the OMIU-reactive Lys analysis of foods, feeds, ingredients, and digesta, was investigated. Crystalline L-Lys incubated under standard conditions with OMIU resulted in low homoarginine recoveries. The reaction of OMIU with the α-amino group of Lys was confirmed by MS analysis, with double derivatized Lys being identified. None of the changes in reaction conditions (OMIU pH, OMIU to Lys ratio, and reaction time) with crystalline L-Lys resulted in 100% recovery of homoarginine. The average free Lys content in ileal digesta of growing pigs and broilers was found to be 13% of total Lys, which could result in a significant underestimation of the reactive Lys content. The reaction of OMIU with α-amino groups may necessitate analysis of free Lys to accurately quantify reactive lysine in samples containing a large proportion of Lys with a free α-amino group.
Original languageEnglish
Pages (from-to)964-972
JournalJournal of Agricultural and Food Chemistry
Volume65
Issue number4
DOIs
Publication statusPublished - 2017

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digesta
Lysine
lysine
food analysis
Homoarginine
ingredients
broiler chickens
swine
Crystalline materials
Food Analysis
Recovery
sampling
O-methylisourea
Swine

Keywords

  • Guanidination reaction
  • Reaction conditions
  • Reactive lysine
  • Specificity

Cite this

@article{7422ee5592064619b88156f82f54784d,
title = "O-methylisourea can react with the α-amino group of lysine: Implications for the analysis of reactive lysine",
abstract = "The specificity of O-methylisourea (OMIU) to bind to the ε-amino group of Lys, an important supposition for the OMIU-reactive Lys analysis of foods, feeds, ingredients, and digesta, was investigated. Crystalline L-Lys incubated under standard conditions with OMIU resulted in low homoarginine recoveries. The reaction of OMIU with the α-amino group of Lys was confirmed by MS analysis, with double derivatized Lys being identified. None of the changes in reaction conditions (OMIU pH, OMIU to Lys ratio, and reaction time) with crystalline L-Lys resulted in 100{\%} recovery of homoarginine. The average free Lys content in ileal digesta of growing pigs and broilers was found to be 13{\%} of total Lys, which could result in a significant underestimation of the reactive Lys content. The reaction of OMIU with α-amino groups may necessitate analysis of free Lys to accurately quantify reactive lysine in samples containing a large proportion of Lys with a free α-amino group.",
keywords = "Guanidination reaction, Reaction conditions, Reactive lysine, Specificity",
author = "Hulshof, {Tetske G.} and Rutherfurd, {Shane M.} and Stefano Sforza and Paul Bikker and {van der Poel}, Thomas and Hendriks, {Wouter H.}",
year = "2017",
doi = "10.1021/acs.jafc.6b03096",
language = "English",
volume = "65",
pages = "964--972",
journal = "Journal of Agricultural and Food Chemistry",
issn = "0021-8561",
publisher = "American Chemical Society",
number = "4",

}

O-methylisourea can react with the α-amino group of lysine : Implications for the analysis of reactive lysine. / Hulshof, Tetske G.; Rutherfurd, Shane M.; Sforza, Stefano; Bikker, Paul; van der Poel, Thomas; Hendriks, Wouter H.

In: Journal of Agricultural and Food Chemistry, Vol. 65, No. 4, 2017, p. 964-972.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - O-methylisourea can react with the α-amino group of lysine

T2 - Implications for the analysis of reactive lysine

AU - Hulshof, Tetske G.

AU - Rutherfurd, Shane M.

AU - Sforza, Stefano

AU - Bikker, Paul

AU - van der Poel, Thomas

AU - Hendriks, Wouter H.

PY - 2017

Y1 - 2017

N2 - The specificity of O-methylisourea (OMIU) to bind to the ε-amino group of Lys, an important supposition for the OMIU-reactive Lys analysis of foods, feeds, ingredients, and digesta, was investigated. Crystalline L-Lys incubated under standard conditions with OMIU resulted in low homoarginine recoveries. The reaction of OMIU with the α-amino group of Lys was confirmed by MS analysis, with double derivatized Lys being identified. None of the changes in reaction conditions (OMIU pH, OMIU to Lys ratio, and reaction time) with crystalline L-Lys resulted in 100% recovery of homoarginine. The average free Lys content in ileal digesta of growing pigs and broilers was found to be 13% of total Lys, which could result in a significant underestimation of the reactive Lys content. The reaction of OMIU with α-amino groups may necessitate analysis of free Lys to accurately quantify reactive lysine in samples containing a large proportion of Lys with a free α-amino group.

AB - The specificity of O-methylisourea (OMIU) to bind to the ε-amino group of Lys, an important supposition for the OMIU-reactive Lys analysis of foods, feeds, ingredients, and digesta, was investigated. Crystalline L-Lys incubated under standard conditions with OMIU resulted in low homoarginine recoveries. The reaction of OMIU with the α-amino group of Lys was confirmed by MS analysis, with double derivatized Lys being identified. None of the changes in reaction conditions (OMIU pH, OMIU to Lys ratio, and reaction time) with crystalline L-Lys resulted in 100% recovery of homoarginine. The average free Lys content in ileal digesta of growing pigs and broilers was found to be 13% of total Lys, which could result in a significant underestimation of the reactive Lys content. The reaction of OMIU with α-amino groups may necessitate analysis of free Lys to accurately quantify reactive lysine in samples containing a large proportion of Lys with a free α-amino group.

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KW - Reaction conditions

KW - Reactive lysine

KW - Specificity

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SN - 0021-8561

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