The Formation, Isolation and Importance of Isopeptides in Heated Proteins

  • Michael Otterburn
  • Michael Healy
  • William Sinclair
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 86)


The separation and resolution of the isopeptides Nε(γ-Lglutamyl)-L-lysine and Nε(β-aspartyl)-L-lysine, formed in heated proteins, has been successfully achieved. The method demands a well characterised ion-exchange column and the use of pH 3.40 lithium citrate buffer (O.2N Li+). Due to variations in particle size and percentage crosslinkages in the ion-exchange resin a computer assisted buffer gradient system has been developed. This system affects resolution of both isopeptides in 7h. The use of leucyl-glycine as an internal standard facilitates quantitative estimation of the isopeptides.

This separative method has been used to analyse a series of heated protein samples and to estimate the quantities of isopeptides formed. The ability of a protein to form isopeptide links is discussed as well as the implication of such links on the reactivity and digestibility of proteins.


Hydrolysis Tyrosine Amide Arginine Glutamine 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer Science+Business Media New York 1977

Authors and Affiliations

  • Michael Otterburn
    • 1
  • Michael Healy
    • 1
  • William Sinclair
    • 1
  1. 1.The Queen’s University of BelfastBelfastN. Ireland

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