Phosphatidylglycerol

Last updated
General chemical structure of a phosphatidyl glycerol where R and R are fatty acid side chains Phosphatidylglycerol.png
General chemical structure of a phosphatidyl glycerol where R and R are fatty acid side chains

Phosphatidylglycerol is a glycerophospholipid found in pulmonary surfactant [1] and in the plasma membrane where it directly activates lipid-gated ion channels.

Contents

The general structure of phosphatidylglycerol consists of a L-glycerol 3-phosphate backbone ester-bonded to either saturated or unsaturated fatty acids on carbons 1 and 2. The head group substituent glycerol is bonded through a phosphomonoester. It is the precursor of surfactant and its presence (>0.3) in the amniotic fluid of the newborn indicates fetal lung maturity.

Approximately 98% of alveolar wall surface area is due to the presence of type I cells, with type II cells producing pulmonary surfactant covering around 2% of the alveolar walls. Once surfactant is secreted by the type II cells, it must be spread over the remaining type I cellular surface area. Phosphatidylglycerol is thought to be important in spreading of surfactant over the Type I cellular surface area. The major surfactant deficiency in premature infants relates to the lack of phosphatidylglycerol, even though it comprises less than 5% of pulmonary surfactant phospholipids. It is synthesized by head group exchange of a phosphatidylcholine enriched phospholipid using the enzyme phospholipase D.

Biosynthesis

Biosynthesis of Phosphatidylglycerol Biosynthesis of phosphatidylglycerol, phosphatidylserine, and phosphatidylethanolamine.svg
Biosynthesis of Phosphatidylglycerol

Phosphatidylglycerol (PG) is formed via a complex sequential pathway whereby phosphatidic acid (PA) is first converted to CDP-diacylglyceride by the enzyme CDP-diacylglyceride synthase. [2] Then a PGP synthase enzyme exchanges glycerol-3-phosphate (G3P) for cytidine monophosphase (CMP), forming the temporary intermediate phosphatidylglycerolphosphate (PGP). [3] PG is finally synthesized when a PGP phosphatase enzyme catalyzes the immediate dephosphorylation of the PGP intermediate to form PG. [4] In bacteria, another membrane phospholipid known as cardiolipin can be synthesized by condensing two molecules of phosphatidylglycerol; a reaction catalyzed by the enzyme cardiolipin-synthase. [5] In eukaryotic mitochondria phosphatidylglycerol is converted to cardiolipin by reacting with a molecule of cytidine diphosphate diglyceride in a reaction catalyzed by cardiolipin synthase. [6]

See also

Related Research Articles

<span class="mw-page-title-main">Lipid</span> Substance of biological origin that is soluble in nonpolar solvents

Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins, monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries, and in nanotechnology.

<span class="mw-page-title-main">Phosphatidylinositol</span> Signaling molecule

Phosphatidylinositol or inositol phospholipid is a biomolecule. It was initially called "inosite" when it was discovered by Léon Maquenne and Johann Joseph von Scherer in the late 19th century. It was discovered in bacteria but later also found in eukaryotes, and was found to be a signaling molecule.

Cardiolipin is an important component of the inner mitochondrial membrane, where it constitutes about 20% of the total lipid composition. It can also be found in the membranes of most bacteria. The name "cardiolipin" is derived from the fact that it was first found in animal hearts. It was first isolated from the beef heart in the early 1940s by Mary C. Pangborn. In mammalian cells, but also in plant cells, cardiolipin (CL) is found almost exclusively in the inner mitochondrial membrane, where it is essential for the optimal function of numerous enzymes that are involved in mitochondrial energy metabolism.

<span class="mw-page-title-main">Plasmalogen</span> Subclass of Glycerophospholipids

Plasmalogens are a class of glycerophospholipid with a plasmenyl group linked to a lipid at the sn-2 position of the glycerol backbone. Plasmalogens are found in multiple domains of life, including mammals, invertebrates, protozoa, and anaerobic bacteria. They are commonly found in cell membranes in the nervous, immune, and cardiovascular systems. In humans, lower levels of plasmalogens are studied in relation to some diseases. Plasmalogens are also associated with adaptations to extreme environments in non-human organisms.

<span class="mw-page-title-main">Inner mitochondrial membrane</span>

The inner mitochondrial membrane (IMM) is the mitochondrial membrane which separates the mitochondrial matrix from the intermembrane space.

<span class="mw-page-title-main">Phospholipid scramblase</span> Protein

Scramblase is a protein responsible for the translocation of phospholipids between the two monolayers of a lipid bilayer of a cell membrane. In humans, phospholipid scramblases (PLSCRs) constitute a family of five homologous proteins that are named as hPLSCR1–hPLSCR5. Scramblases are members of the general family of transmembrane lipid transporters known as flippases. Scramblases are distinct from flippases and floppases. Scramblases, flippases, and floppases are three different types of enzymatic groups of phospholipid transportation enzymes. The inner-leaflet, facing the inside of the cell, contains negatively charged amino-phospholipids and phosphatidylethanolamine. The outer-leaflet, facing the outside environment, contains phosphatidylcholine and sphingomyelin. Scramblase is an enzyme, present in the cell membrane, that can transport (scramble) the negatively charged phospholipids from the inner-leaflet to the outer-leaflet, and vice versa.

In enzymology, a 7alpha-hydroxysteroid dehydrogenase (EC 1.1.1.159) is an enzyme that catalyzes the chemical reaction

In enzymology, a phosphatidylcholine desaturase (EC 1.14.19.22, previously EC 1.3.1.35) is an enzyme that catalyzes the chemical reaction

Palmitoyl-CoA hydrolase (EC 3.1.2.2) is an enzyme in the family of hydrolases that specifically acts on thioester bonds. It catalyzes the hydrolysis of long chain fatty acyl thioesters of acyl carrier protein or coenzyme A to form free fatty acid and the corresponding thiol:

<span class="mw-page-title-main">Phosphatidate phosphatase</span>

The enzyme phosphatidate phosphatase (PAP, EC 3.1.3.4) is a key regulatory enzyme in lipid metabolism, catalyzing the conversion of phosphatidate to diacylglycerol:

In enzymology, a [acyl-carrier-protein] S-malonyltransferase is an enzyme that catalyzes the chemical reaction

In enzymology, a globotriaosylceramide 3-beta-N-acetylgalactosaminyltransferase is an enzyme that catalyzes the chemical reaction

In enzymology, a CDP-diacylglycerol—glycerol-3-phosphate 3-phosphatidyltransferase is an enzyme that catalyzes the chemical reaction

<span class="mw-page-title-main">PLSCR3</span> Protein-coding gene in the species Homo sapiens

Phospholipid scramblase 3 is an enzyme that in humans is encoded by the PLSCR3 gene. Like the other phospholipid scramblase family members, PLS3 is a type II plasma membrane protein that is rich in proline and integral in apoptosis, or programmed cell death. The regulation of apoptosis is critical for both cell development and tissue homeostasis

Archaeol is a diether composed of two phytanyl chains linked to the sn-2 and sn-3 positions of glycerol. As its phosphate ester, it is a common component of the membranes of archaea.

<span class="mw-page-title-main">1-Lysophosphatidylcholine</span>

1-Lysophosphatidylcholines are a class of phospholipids that are intermediates in the metabolism of lipids. They result from the hydrolysis of an acyl group from the sn-1 position of phosphatidylcholine. They are also called 2-acyl-sn-glycero-3-phosphocholines. The synthesis of phosphatidylcholines with specific fatty acids occurs through the synthesis of 1-lysoPC. The formation of various other lipids generates 1-lysoPC as a by-product.

Pyruvate dehydrogenase (quinone) (EC 1.2.5.1, pyruvate dehydrogenase, pyruvic dehydrogenase, pyruvic (cytochrome b1) dehydrogenase, pyruvate:ubiquinone-8-oxidoreductase, pyruvate oxidase (ambiguous)) is an enzyme with systematic name pyruvate:ubiquinone oxidoreductase. This enzyme catalyses the following chemical reaction

Beta-carotene 3-hydroxylase (EC 1.14.13.129, beta-carotene 3,3'-monooxygenase, CrtZ) is an enzyme with systematic name beta-carotene,NADH:oxygen 3-oxidoreductase . This enzyme catalyses the following chemical reaction

(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase is an enzyme with systematic name UDP-N-acetyl-D-galactosamine:1-O-(O- - -O-beta-D-galactopyranosyl- -beta-D-glucopyranosyl)-ceramide 4-beta-N-acetyl-D-galactosaminyltransferase. This enzyme catalyses the following chemical reaction:

Diacylglycerol diphosphate phosphatase (EC 3.1.3.81, DGPP phosphatase, DGPP phosphohydrolase, DPP1, DPPL1, DPPL2, PAP2, pyrophosphate phosphatase) is an enzyme with systematic name 1,2-diacyl-sn-glycerol 3-phosphate phosphohydrolase. This enzyme catalyses the following chemical reaction

References

  1. ↑ Richard J. King; Mary Catherine MacBeth (6 October 1981). "Interaction of the lipid and protein components of pulmonarysurfactant Role of phosphatidylglycerol and calcium". Biochimica et Biophysica Acta (BBA) - Biomembranes. 647 (2): 159–168. doi:10.1016/0005-2736(81)90242-X. PMID   6895322.
  2. ↑ Dowhan, W. (1997-09-04). "CDP-diacylglycerol synthase of microorganisms". Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 1348 (1–2): 157–165. doi:10.1016/s0005-2760(97)00111-2. ISSN   0006-3002. PMID   9370328.
  3. ↑ Pluschke, G.; Hirota, Y.; Overath, P. (1978-07-25). "Function of phospholipids in Escherichia coli. Characterization of a mutant deficient in cardiolipin synthesis". Journal of Biological Chemistry. 253 (14): 5048–5055. doi: 10.1016/S0021-9258(17)34655-0 . ISSN   0021-9258.
  4. ↑ Dillon, Deirdre A.; Wu, Wen-I; Riedel, Bettina; Wissing, Josef B.; Dowhan, William; Carman, George M. (November 1996). "The Escherichia coli pgpB Gene Encodes for a Diacylglycerol Pyrophosphate Phosphatase Activity". Journal of Biological Chemistry. 271 (48): 30548–30553. doi: 10.1074/jbc.271.48.30548 . PMID   8940025.
  5. ↑ Nishijima, S; Asami, Y; Uetake, N; Yamagoe, S; Ohta, A; Shibuya, I (February 1988). "Disruption of the Escherichia coli cls gene responsible for cardiolipin synthesis". Journal of Bacteriology. 170 (2): 775–780. doi:10.1128/jb.170.2.775-780.1988. ISSN   0021-9193. PMC   210721 . PMID   2828323.
  6. ↑ Hostetler KY, van den Bosch H, van Deenen LL (March 1972). "The mechanism of cardiolipin biosynthesis in liver mitochondria". Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 260 (3): 507–13. doi:10.1016/0005-2760(72)90065-3. hdl: 1874/17621 . PMID   4556770. S2CID   46101728.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.