Hemeprotein

Part of speech: noun

Definitions

1. A protein that has an iron-containing heme group bound to it, such as hemoglobin or myoglobin
2. Any of a class of proteins whose structure includes a heme prosthetic group that binds oxygen or carries out electron transfer
3. A conjugated protein built around a heme unit, found in blood, muscle and many enzymes involved in respiration

Etymology: Hemeprotein is a compound formed from two parts: "heme," the iron-bearing ring molecule that binds oxygen, and "protein," the chain of amino acids it attaches to. The word is a plain technical coinage, built by joining these two terms, and it names the whole class of proteins that carry a heme group. Hemoglobin and myoglobin are the best-known examples. The first half, "heme," comes from the Greek "haima," meaning blood, which also gives English "hemo-" in words like "hemorrhage." That link explains the logic of the name: the molecule was identified in blood, where its iron gives blood its red colour. "Protein" itself comes from the Greek "prōteios," meaning "primary" or "of first importance," a name chosen in the 1830s by the chemist Gerardus Johannes Mulder, who thought these substances were the foundation of living matter.

Synonyms: hemoprotein, haemoprotein