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Lipoprotein


DATA No : TLP1401 INFORMANT : Kazuo Kondo

NAME : Chylomicrons

COMMON NAME: Chylomicrons
SYMBOL: chylos
FORMULA: MOL.WT (average) :
BIOLOGICAL ACTIVITY
Biological activities
Chylomicrons transport dietary triglyceride from the intestine to peripheral tissues and cholesterol to the liver.
(Ref. 1406)
PHYSICAL AND CHEMICAL PROPERTIES
MELTING POINT:Defination
Chylomicrons is defined as the lipoprotein fraction with the density below 0.93
(Ref. 1401)

BOILING POINT:

REFRACTIVE INDEX:

OPTICAL ROTATION:

DENSITY:below 0.93 g/ml
(Ref. 1401)

SOLUBILITY:Physical properties
Particle weight below 4times108 Diameter nm 75-1200
Relative weght Composition (%) of Human Plasma Lipoproteins
Protein 1-2% Phospholipid 19% Free cholesterol 1.6% Cholesterol ester 1.4% Triglyceride %
Apolipoprotein contribution% apoB 5-20 apoC 70-80 apo E4
(Ref. 1401)
SPECTRAL DATA
UV SPECTRA:

IR SPECTRA:

NMR SPECTRA:

MASS SPECTRA:

OTHER SPECTRA:
CHROMATOGRAM DATA
Chylomicrons on agarose gel electrophoresis
In agarose gel electrophoresis Chylomicrons remains at origin.
SOURCE

CHEMICAL SYNTHESIS
Structure of Chylomicrons
Chylomicrons is a spherical particle and in normal individuals ranges 75 to 1200 nm in diameter. The average molecular weight is below 4times108 .Compared with other lipoproteins , Chylomicrons particles are relatively heterogeneous in size and composition . Chylomicrons consists of Protein 1-2% Phospholipid 19% Free cholesterol 1.6% Cholesterol ester 1.4% Triglyceride 88%
Apolipoprotein contribution% apoB 5-20 (mainly apoB48) apoC 70-80 apoE 4 on Chylomicrons. It is presumed that the cholesteryl esters and triglycerides form the hydrophobic core, which is surrounded by a surface coat of apolipoprotein B48, free cholesterol and polar phospholipid components oriented toward the aqueous medium.
(Ref. 1401/1402/1403/1404/1405)
METABOLISM
Metabolism of Chylomicrons
Chylomicrons are formed in the intestine and transport dietary triglyceride to peripheral tissues and cholesterol to the liver. The enzyme lipoprotein lipase, with apolipoprotein (apo)C-II as a co-factor, hydrolyzes chylomicron triglyceride allowing the delivery of free fatty acids to muscle and adipose tissue. As a result, a new particle called a chylomicron remnant is formed.The chylomicron remnants are rapidly taken up into the liver via the LDL receptor and the LDL receptor-related protein.
(Ref. 1401/1406/1407)
GENETIC INFORMATION

NOTE

REFERENCES
[1401]
AUTHOR:Gotto,A.M. Jr., Pownall,H.J. and Havel,R.L.
TITLE:Introduction to the Plasma Lipoproteins. PubMed ID:3523141
JOURNAL:Methods Enzymol.
VOL:128 PAGE : 3 -41 (1986)
[TOP]

[1402]
AUTHOR:Alaupovic,P., Lee,D.M., and WcConathy, W.J.
TITLE: Studies on the Composition and Structure of Plasma Lipoproteins. Distribution of Lipoprotein Families in Major Density Classes of Normal Human Plasma Lipoproteins. PubMed ID:4337564
JOURNAL:Biochem.Biophys.Acta
VOL:260 PAGE : 689 -707 (1972)
[TOP]

[1403]
AUTHOR:Eisenberg,S. Steiner,G. and Shafrir,E., eds.
TITLE:Plasma Lipoproteins : Structure,Composition,Classification and Metabolism in Primary Hyperlipoproteinemias.
JOURNAL:McGraw-Hill
VOL: PAGE : 23 -41 (1991)
[TOP]

[1404]
AUTHOR:Eisenberg,S., and Levy,R.I.
TITLE:Lipoprotein Metabolism. PubMed ID:174409
JOURNAL:Adv Lipid Res.
VOL:13 PAGE : 1 -89 (1975)
[TOP]

[1405]
AUTHOR:Jacson,R.l.,Morrisett,J.D. and Gotto,A.M.Jr.
TITLE:Lipoprotein Structure and Metabolism.
JOURNAL:Physiol.Rev.
VOL:56 PAGE : 259 -316 (1976)
[TOP]

[1406]
AUTHOR:Cooper, A. D.
TITLE:Hepatic uptake of chylomicron remnants PubMed ID:9392416
JOURNAL:J Lipid Res.
VOL:38 PAGE : 2173-2192 (1997)
[TOP]

[1407]
AUTHOR:Beisiegel, U.
TITLE:Lipoprotein metabolism PubMed ID:9519338
JOURNAL:Eur Heart J.
VOL:19 Suppl A PAGE : A20-23 (1998)
[TOP]

Last updated June 19, 2007. Copyright © 1989-2007 Japanese Conference on the Biochemistry of Lipids (JCBL). All rights reserved.