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Biosynthesis of Glycerophospholipids

also known asPhosphoglycerides or Phosphoacylglycerol

Lippincott’s Ch 17

GLYCEROL

FATTY ACID

FATTY ACID

PHOSPHOACYLGLYCEROL

PHOSPHATEALCOHOL

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O║

O CH2O-C-R1║ I

R2C-OCHICH2O- -

Phosphatidic Acid

Can Form Ester with Alchol:

- Serine - Inositol

- Ethanolamine - Glycerol

- Choline

Phosphatidyl -

P

HO-CH2 CH3

Ethanol

HO-CH2CH2-NH3+

Ethanolamine

HO-CH2 CH2 –N(CH3)3+

Choline

HO-CH2 CH-NH3+

ICOO-

Serine

Structural Relationship among polar head groups of phospholipids

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O║

O CH2O-C-R1║ I

R2C-OCH +I - CH3CH2O- - O-CH2 CH2 –NCH3

CH3

Phosphatidyl Choline (Lecithin)

P

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?

??

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GLYCEROL

FATTY ACID

FATTY ACID

Degradation of Phospholipids:Phospholipase A1

Phospholipase A2

Phospholipase CPhospholipase D

PHOSPHATE

ALCOHOL

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Biosynthesis of Triacylglycerol & Phosphoacylglycerol

GLYCEROL

FATTY ACID

FATTY ACID

FATTY ACID

TRIACYLGLYCEROL

GLYCEROL

FATTY ACID

FATTY ACID

PHOSPHOACYLGLYCEROL

PHOSPHATE

ALCOHOL

Phosphotadic Acid is Common Intermediate

GLYCEROL

FATTY AC ID

FATTY AC ID

PH O S P H O AC YLG LYC E R O L

P H O S P H ATE

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GLYCEROL

FATTY ACID

FATTY ACID

PHOSPHATE

ALCOHOL

Biosynthesis of glycerophospholipids

Alcohol1 Phosphate Alcohol2

Transfer ~(Phosphate-Alcohol1) to Alcohol2 or

Transfer ~(Phosphate-Alcohol2) to Alcohol1

Formation of Activated Carrier

Alcohol- P P P P

Ribose-Cytosine

Alcohol- P P

Ribose-Cytosine

P P

CDP-Alcohol Pyrophosphate

~~

~~

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Synthesis of Phosphatidyl InositolTransfer or Phosphatidic acid to Inositol

CDP-diacylglycerol + Inositol

CMP Phosphatidyl Inositol

Synthesis of Phosphatidyl Choline

Transfer or Phosphocholine (Ethanolamine) to Diacylglycerol

CDP-Choline Diacylglycerol

CMP Phosphatidyl Choline

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Alteration of Polar Head Group• Exchange of the Polar Head Group

Phosphatidyl Ethanolamine Serine

• Phosphatidyl Serine Ethanolamine

Alteration of Polar Head Group• Decarboxylation of Phosphatidyl Serine

Phosphatidyl Serine

CO2

Phosphatidyl Ethanolamine

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Alteration of Polar Head Group• Methylation of Phosphatidyl Ethanolamine

S- Adenosyl Methionine (SAM); Methyl donor

Phosphatidyl Ethanolamine

Phosphatidyl Choline

CH3-S-CH2CH2-CH-COO-

I IAdenosine NH3+

S- Adenosyl Homocysteine

S-CH2CH2-CH-COO-

I IAdenosine NH3+

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Remodeling Phospholipids: Changing the Fatty Acid

Ether Glycerophospholipids

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Platelet-activating Factor

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Surfactant Action of Phospholipids

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