---
title: "Pyroglutamate: research glossary | Sable Peptides"
description: "Pyroglutamate is a cyclic derivative formed when an N-terminal glutamine or glutamic acid cyclises to form a lactam. Formation from glutamine releases ammo"
canonical: https://www.sablepeptides.co.uk/glossary/pyroglutamate
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

Glossary

# Pyroglutamate

Pyroglutamate is a cyclic derivative formed when an N-terminal glutamine or glutamic acid cyclises to form a lactam. Formation from glutamine releases ammonia and reduces mass by about 17 Da, while formation from glutamic acid releases water, reducing mass by about 18 Da. It blocks the N-terminus and may form during storage of susceptible peptides.

Source: [en.wikipedia.org](https://en.wikipedia.org/wiki/Pyroglutamic_acid)

## Related terms

-   [N-terminus](/glossary/n-terminus)
-   [Glutamine](/glossary/glutamine)
-   [Glutamic acid](/glossary/glutamic-acid)

[Back to glossary A–Z](/glossary/terms)

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