Protoporphyrin

Protoporphyrin

Protoporphyrins are tetrapyrroles containing the following side chains:

* methyl (4)
* propionic acid (2)
* vinyl (2)

Protoporphyrin IX is a biochemically widely used carrier molecule for divalent cations, e.g. together with iron (Fe 2+) the body of the heme- groupe of hemoglobin, myoglobin and many other heme- containing enzymes like cytochrome c and catalase is formed, complexed with magnesium-ions (Mg 2+) the main part of the Chlorophylls are formed.

The number (e.g. IX) indicates the position of different side cains, but the nomenclatur is historically grown and only in parts sytematically.

Protoporphyrin IX as a direct precursor of heme is accumulated by patients of erythropoietic protoporphyria, which is one of the genetic disorders of the biosynthesis of the heme -pathway. It causes a severe photosensivity against visible light.

The sensivity of protoporphyrin IX against light is also used as a therapy against different forms of cancer (photodynamic therapy, PDT).

Protoporphyrins are deposited in the shells of the eggs of some birds as a brown or red pigment, either as a ground colour or as spotting. This occurs in most passerine species, some ground-nesting non-passerines, such as waders, gulls, nightjars and sandgrouse, where it provides camouflage, and some parasitic cuckoos, which need to mimic their passerine hosts' eggs.

Protoporphyrins strengthen the egg shell, and are deposited where the shell is too thin as a result of calcium shortage. Spotting therefore tend to be heavier where the local soil is calcium-deficient, and in the eggs laid last in a clutch.

External links

*
* - protoporphyrin IX


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  • Protoporphyrin — Strukturformel des Porphyrin Gerüst mit Nummerierung. Strukturformel von Protoporphyrin IX. Porphyrine (nach griechisch πορφυρά, porphyrá, dem …   Deutsch Wikipedia

  • Protoporphyrin IX — Strukturformel des Porphyrin Gerüst mit Nummerierung. Strukturformel von Protoporphyrin IX. Porphyrine (nach griechisch πορφυρά, porphyrá, dem …   Deutsch Wikipedia

  • Protoporphyrin IX — chembox new ImageFile = Protoporphyrin IX.svg OtherNames = Formula = C34H34N4O4 PubChem = 4971 MolarMass= 562.658 g/mol CASNo = 553 12 8 Density= MeltingPt= BoilingPt=In the metabolism of porphyrin, protoporphyrin IX is created by the enzyme… …   Wikipedia

  • protoporphyrin — Porphyrin ring structure lacking metal ions. The most abundant is protoporphyrin IX, the immediate precursor of haem …   Dictionary of molecular biology

  • Protoporphyrin — Pro|to|por|phy|rin [↑ proto ] Syn.: Protoporphyrin IX: Trivialname für ein achtfach substituiertes ↑ Porphyrin (C34H34N4O4), von dem sich u. a. Hamätoporphyrin u. Häm sowie Chlorophyll ableiten …   Universal-Lexikon

  • protoporphyrin — pro·to·por·phy·rin .prōt ō pȯr f(ə )rən n a purple porphyrin acid C34H34N4O4 obtained from hemin or heme by removal of bound iron * * * pro·to·por·phy·rin (pro″to porґfə rin) the porphyrin produced by oxidation of the methylene bridge …   Medical dictionary

  • protoporphyrin type III — The principal protoporphyrin found in nature (one of 15 possible isomers), characterized by the presence of four methyl groups, two vinyl groups, and two propionic acid side chains; a porphyrin derivative that, with iron, forms the heme of… …   Medical dictionary

  • protoporphyrin — noun Etymology: International Scientific Vocabulary Date: 1925 a purple porphyrin acid C34H34N4O4 obtained from hemin or heme by removal of bound iron …   New Collegiate Dictionary

  • protoporphyrin — pro·to·por·phy·rin (prō tō pôrʹfə rĭn) n. A metal free porphyrin, C32H32N4(COOH)2, that combines with ferrous iron to form the heme group in hemoglobin and myoglobin, and with ferric iron to form the hemin group in catalase and some cytochromes.… …   Universalium

  • protoporphyrin — noun Any porphyrin that lacks a central metal ion …   Wiktionary

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