histidine

American  

[his-ti-deen, -din] / ˈhɪs tɪˌdin, -dɪn /

Also histidin

noun

Biochemistry.

1. an essential amino acid, C 3 H 3 N 2 CH 2 CH(NH2 )COOH, that is a constituent of proteins and is important as the iron-binding site in hemoglobin. His; H

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histidine British  

/ ˈhɪstɪˌdiːn, -dɪn /

noun

1. a nonessential amino acid that occurs in most proteins: a precursor of histamine

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histidine Scientific  

/ hĭs′tĭ-dēn′ /

1. An amino acid that is essential for children but not for adults. Chemical formula: C ₆ H ₉ N ₃ O ₂ .

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Etymology

Origin of histidine

First recorded in 1895–1900; hist- + -id ³ + -ine ²

Example Sentences

At the same time, certain microbes help eliminate the amino acid histidine.

From Science Daily • Feb. 25, 2026

This was not the feared 226L mutation: The amino acid had changed to a histidine instead of leucine.

From Science Magazine • Dec. 5, 2024

The sequencing data revealed a variant that substituted an amino acid called histidine for arginine.

From Scientific American • Jul. 26, 2021

And a molecule of histidine contains only so many suitable atoms.

From Economist • Feb. 23, 2012

Nothing is known, however, of the process by which the more complicated closed-ring amino-acid compounds, such as proline, histidine, or tryptophane, are synthetized.

From The Chemistry of Plant Life by Thatcher, Roscoe Wilfred