prosthetic groups

A prosthetic group is a non-protein (non-amino acid) component of a conjugated protein. The prosthetic group may be organic (such as a vitamin, sugar, or lipid) or inorganic (such as a metal ion). Prosthetic groups usually bond covalently to their protein. They often play an important role in the function of many proteins such as enzymes. A good example of a prosthetic group is the heme group in hemoglobin. A protein without its prosthetic group is called an apoprotein, while a protein combined with its prosthetic group is called a holoprotein.

Prosthetic groups are also sometimes called coenzymes or cofactors because they are essential to the function of a protein. In enzymes, prosthetic groups are involved in the active site in some way. Further examples of organic prosthetic groups are vitamin derivatives: thiamine (vitamin B1), thiamine pyrophosphate, pyridoxine (Vitamin B6), pyridoxal-phosphate. This is another reason why vitamins are so important in our diet. Inorganic prosthetic groups are usually transition metal ions such as iron (in heme groups, for example in cytochrome c oxidase and hemoglobin), zinc (for example in carbonic anhydrase),magnesium (for example in some kinases), and molybdenum (for example in nitrate reductase).

See also

amino acid is a molecule that contains both amine and carboxyl functional groups. In biochemistry, this term refers to alpha-amino acids with the general formula H2NCHRCOOH, where R is an organic substituent.
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A conjugated protein is a protein that functions in interaction with other chemical groups attached by covalent bonds or by weak interactions.

Many proteins contain only amino acids and no other chemical groups, and they are called simple proteins.
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organic compounds]] An organic compound is any member of a large class of chemical compounds whose molecules contain carbon; for historical reasons discussed below, a few types of compounds such as carbonates, carbon oxides and cyanides, as well as elemental carbon are
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A vitamin is a nutrient that is an organic compound required in tiny amounts for essential metabolic reactions in a living organism.[1] The term vitamin
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Sugars, brown
Nutritional value per 100 g (3.5 oz)

Energy 0 kcal   0 kJ

Carbohydrates     97.33 g
- Sugars  96.21 g
- Dietary fiber  0 g  
Fat 0 g
Protein 0 g
Water 1.77 g
Thiamin (Vit. B1)  0.
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Lipids can be broadly defined as any fat-soluble (hydrophobic), naturally-occurring molecules. The term is more-specifically used to refer to fatty-acids and their derivatives (including tri-, di-, and monoglycerides and phospholipids) as well as other fat-soluble sterol-containing
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inorganic compounds are considered to be of mineral, not biological, origin. Complementarily, most organic compounds are traditionally viewed as being of biological origin.
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The Macro Expansion Template Attribute Language complements TAL, providing macros which allow the reuse of code across template files. Both were created for Zope but are used in other Python projects as well.
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Covalent bonding is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms, or between atoms and other covalent bonds.
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Enzymes are proteins that catalyze (i.e. accelerate) chemical reactions.[1] In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, the products.
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A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. Not all porphyrins contain iron, but a substantial fraction of porphyrin-containing metalloproteins have heme as
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Hemoglobin, also spelled haemoglobin and abbreviated Hb, is the iron-containing oxygen-transport metalloprotein in the red blood cells of the blood in vertebrates and other animals.
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An apoprotein is a protein without its characteristic prosthetic group.

Apoproteins are lipid-binding proteins present in chylomicrons, absorbed by Enterocytes within the small intestines and colonocytes in the colon.
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Holoprotein is an apoprotein combined with its prosthetic group.
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Coenzymes are small organic non-protein molecules that carry chemical groups between enzymes. They are substrates for enzymes and do not usually form a permanent part of the enzymes' structures.
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EC1 Oxidoreductases/list - EC2 Transferases/list - EC3 Hydrolases/list - EC4 Lyases/list - EC5 Isomerases/list - EC6 Ligases/list
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The active site of an enzyme contains the catalytic and binding sites. The structure and chemical properties of the active site allow the recognition and binding of the substrate.
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For the similarly spelled nucleic acid, see Thymine


Thiamine or thiamin, also known as vitamin B1 and aneurine hydrochloride, is one of the B vitamins.
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Pyridoxal-phosphate (PLP, pyridoxal-5'-phosphate) is a coenzyme of many enzymatic reactions. It is the active form of vitamin B 6 which comprises three natural organic compounds, pyridoxal, pyridoxamine and pyridoxine.
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3, 4, 6
(amphoteric oxide)
Electronegativity 1.83 (Pauling scale)
Ionization energies
(more) 1st: 762.5 kJmol−1
2nd: 1561.9 kJmol−1
3rd: 2957 kJmol−1

Atomic radius 140 pm
Atomic radius (calc.
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A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. Not all porphyrins contain iron, but a substantial fraction of porphyrin-containing metalloproteins have heme as
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cytochrome c oxidase or Complex IV (PDB 2OCC , EC 1.9.3.1 ) is a large transmembrane protein complex found in bacteria and the mitochondrion.

Function

It is the last protein in the electron transport chain.
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Hemoglobin, also spelled haemoglobin and abbreviated Hb, is the iron-containing oxygen-transport metalloprotein in the red blood cells of the blood in vertebrates and other animals.
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Zinc (IPA: /ˈzɪŋk/, from German: Zink) is a chemical element in the periodic table that has the symbol Zn and atomic number 30.
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Carbonic anhydrase (carbonate dehydratase) is a family of metalloenzymes (enzymes that contain one or more metal atoms as a functional component of the enzyme) that catalyze the rapid conversion of carbon dioxide to bicarbonate and protons, a reaction that occurs rather
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Magnesium has the symbol Mg, the atomic number 12, and an atomic mass of 24.31. Magnesium is the ninth most abundant element in the universe by mass. It constitutes about 2% of the Earth's crust by mass, and it is the third most abundant element dissolved in seawater.
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In chemistry and biochemistry, a kinase, alternatively known as a phosphotransferase, is a type of enzyme that transfers phosphate groups from high-energy donor molecules, such as ATP, to specific target molecules (substrates); the process is termed phosphorylation
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6
(strongly acidic oxide)
Electronegativity 2.16 (scale Pauling)
Ionization energies
(more) 1st: 684.3 kJmol−1
2nd: 1560 kJmol−1
3rd: 2618 kJmol−1
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Nitrate reductase enzymes are a group of enzymes which reduce nitrate to nitrite.
  • Nitrate reductase (1)- is a large and complex enzyme ; has multiple subunits and ~ 800 kD. Contains bound FAD, Mo, and cytochrome 557 and has ferredoxin Fe4S4 center.

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EC1 Oxidoreductases/list - EC2 Transferases/list - EC3 Hydrolases/list - EC4 Lyases/list - EC5 Isomerases/list - EC6 Ligases/list
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