Lipoproteins

complexes of proteins and lipids. Lipoproteins occur in plants and animals as constituents of all biological membranes and lamellar structures (in the myelin sheath of nerves, in the chloroplasts of plants, in the receptor cells of the retina). They occur in free form in blood plasma, from which they were first isolated in 1929.

Lipoproteins are classified according to chemical structure and lipid-protein ratio. They are subdivided into four main classes according to sedimentation rate during centrifugal separation: (1) high-density lipoproteins (52 percent protein and 48 percent lipids, primarily phospholipids), (2) low-density lipoproteins (21 percent protein and 79 percent lipids, mainly cholesterol), (3) very low-density lipoproteins (9 percent protein and 91 percent lipids, mostly triglycerides), and (4) chylomicrons (1 percent protein and 99 percent triglycerides).

It is thought that lipoprotein structure is micellar (the protein bonded to the lipid-cholesterol complex owing to hydrophobic interaction) or analogous to that of molecular compounds of proteins and lipids (the phospholipid molecules located in flexures of the polypeptide chains of protein subunits). The study of lipoproteins is complicated by the instability of lipid-protein complexes and by difficulties encountered in their isolation in natural form.

REFERENCE

Finean, J. Biologicheskie ul’trastruktury. Moscow, 1970. (Translated from English.)

N. V. PROKAZOVA

lipoproteins

Any complex of fats with protein. A conjugated protein consisting of a simple protein combined with a fat (lipid) group. The blood lipoproteins, which are the cholesterol carriers of the body, are classified by density, in accordance with the proportions of protein, as very low density (VLDL), low density (LDL) and high density (HDL). LDLs contain relatively large amounts of cholesterol. HDLs contain 50% of protein and only 20% of cholesterol. LDLs transport lipids to muscles and to fat stores and are associated with the arterial disease ATHEROSCLEROSIS and thus heart disease and STROKE. HDLs are protective against these diseases because their main role is to transport cholesterol from the periphery back to the liver. They also carry paraoxanase enzymes that limit oxidative modification of LDLs necessary before cholesterol can be laid down in arterial walls. Blood concentration of HDL cholesterol shows a strong inverse correlation with the risk of coronary heart disease.

Lipoproteins

The packages in which cholesterol and triglycerides travel throughout the body.Mentioned in: Lipoproteins Test

Patient discussion about lipoproteins

Q. what are the sources for high density lipoprotein? I have heard that high density lipoprotein is good for heart. What differences does it make in heart’s health and what are the sources for high density lipoprotein?A. Hi Liam, it is very important that we have high density lipoprotein (HDL) in our body. The fact is that the HDL is formed inside the body. They are known as good cholesterol as they are famous for their protection for heart against the heart diseases. It has been found that Vitamin B3 or Niacin consumption increases the count of HDL. It’s good to cut on the diet having more of saturated fats and oils, which increases the chances of heart attack.

More discussions about lipoproteins

单词	lipoproteins
释义	lipoproteins Translations Lipoproteins Lipoproteins complexes of proteins and lipids. Lipoproteins occur in plants and animals as constituents of all biological membranes and lamellar structures (in the myelin sheath of nerves, in the chloroplasts of plants, in the receptor cells of the retina). They occur in free form in blood plasma, from which they were first isolated in 1929. Lipoproteins are classified according to chemical structure and lipid-protein ratio. They are subdivided into four main classes according to sedimentation rate during centrifugal separation: (1) high-density lipoproteins (52 percent protein and 48 percent lipids, primarily phospholipids), (2) low-density lipoproteins (21 percent protein and 79 percent lipids, mainly cholesterol), (3) very low-density lipoproteins (9 percent protein and 91 percent lipids, mostly triglycerides), and (4) chylomicrons (1 percent protein and 99 percent triglycerides). It is thought that lipoprotein structure is micellar (the protein bonded to the lipid-cholesterol complex owing to hydrophobic interaction) or analogous to that of molecular compounds of proteins and lipids (the phospholipid molecules located in flexures of the polypeptide chains of protein subunits). The study of lipoproteins is complicated by the instability of lipid-protein complexes and by difficulties encountered in their isolation in natural form. REFERENCE Finean, J. Biologicheskie ul’trastruktury. Moscow, 1970. (Translated from English.) N. V. PROKAZOVA lipoproteins lipoproteins Any complex of fats with protein. A conjugated protein consisting of a simple protein combined with a fat (lipid) group. The blood lipoproteins, which are the cholesterol carriers of the body, are classified by density, in accordance with the proportions of protein, as very low density (VLDL), low density (LDL) and high density (HDL). LDLs contain relatively large amounts of cholesterol. HDLs contain 50% of protein and only 20% of cholesterol. LDLs transport lipids to muscles and to fat stores and are associated with the arterial disease ATHEROSCLEROSIS and thus heart disease and STROKE. HDLs are protective against these diseases because their main role is to transport cholesterol from the periphery back to the liver. They also carry paraoxanase enzymes that limit oxidative modification of LDLs necessary before cholesterol can be laid down in arterial walls. Blood concentration of HDL cholesterol shows a strong inverse correlation with the risk of coronary heart disease. Lipoproteins The packages in which cholesterol and triglycerides travel throughout the body.Mentioned in: Lipoproteins Test Patient discussion about lipoproteins Q. what are the sources for high density lipoprotein? I have heard that high density lipoprotein is good for heart. What differences does it make in heart’s health and what are the sources for high density lipoprotein?A. Hi Liam, it is very important that we have high density lipoprotein (HDL) in our body. The fact is that the HDL is formed inside the body. They are known as good cholesterol as they are famous for their protection for heart against the heart diseases. It has been found that Vitamin B3 or Niacin consumption increases the count of HDL. It’s good to cut on the diet having more of saturated fats and oils, which increases the chances of heart attack. More discussions about lipoproteins ThesaurusSeelipoprotein
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