Heme (American English), or haem (Commonwealth English, both pronounced /hi:m/ HEEM), is a ring-shaped iron-containing molecular component of hemoglobin, which is necessary to bind oxygen in the bloodstream.

May 1, 2023 · Heme is an essential prosthetic group in proteins that is necessary as a subcellular compartment to perform diverse biological functions like hemoglobin and myoglobin. [1] . Other enzymes which use heme as a prosthetic group includes cytochromes of the electron transport chain, catalase, and nitric oxide synthase.

Heme, or haem (pronounced /hi:m/ HEEM), is a precursor to hemoglobin. It is necessary to bind oxygen in the circulatory system. Heme is made in both the bone marrow and the liver.

Heme B or haem B (also known as protoheme IX) is the most abundant heme. [1] Hemoglobin and myoglobin are examples of oxygen transport proteins that contain heme B. The peroxidase family of enzymes also contain heme B.

Oct 19, 2022 · Here we show that haem-responsive gene 9 (HRG-9) (also known as transport and Golgi organization 2 (TANGO2)) is an evolutionarily conserved haem chaperone with a crucial role in trafficking...

Mar 25, 2025 · Here we demonstrate that haem biosynthesis is the primary source of haem in brown adipocytes. Inhibiting haem biosynthesis results in an accumulation of the branched-chain amino acids (BCAAs)...

Jun 6, 2008 · We propose a model of haem homeostasis in which CeHRG-4 mediates haem uptake in C. elegans at the plasma membrane, whereas CeHRG-1 regulates intracellular haem availability through an endosomal compartment (Fig. 4h). Haem limitation would induce the uptake and regulated sequestration of an essential, but toxic, macrocycle by the coordinated ...

Mar 15, 2018 · Heme has two understood functions. It can bind gases, such as oxygen, and transport them throughout an organism. Special proteins then force the heme to release its oxygen at the appropriate time. A good example of a protein of this type is hemoglobin.

Apr 27, 2018 · Haem is an iron ion coordinated to a substituted porphyrin ring, called protoporphyrin IX (PPIX) and serves as a cofactor for a functionally diverse group of proteins. The porphyrin ring can be structurally modified to produce haem types b, c, a, o or d.

Recent advances in haem transport have led to the identification of both haem-import and haem-efflux proteins. HCP1, which is strongly expressed in the duodenum, is thought to mediate haem import into enterocytes.