Lecture 14 - Lipoprotein Structure and Receptor Function

Lecture 14 - Lipoprotein Structure and Receptor Function -...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 14 – Lipoprotein Structure and Receptor Function Definitions Lipoproteins - a macromolecular complex of proteins with cholesterol and cholesterol esters (cholesterol in the blood is mostly in ester form), triglycerides and phospholipids comprise most of the lipoprotein Apoprotein - is just the protein part that is complexed with the lipid and has some activator function. They are not just structural but they are the protein part of the complex (often enzymatic or receptor-ligand function Cylomicron - The first kind of lipoprotein - Large lipoprotein made mostly of triglycerides and we make it in the GI tract to ship dietary lipids to the liver o The fat gets broken down in the intestine & then into fatty acids and other components that are taken up by intestinal epithelial cells and those cells package the fat in the form of chylomicrons and sends it out. - It packages the fat along with the specific protein (apoB48) and this is the protein that is most associated with chylomicrons. - If you just ate breakfast and you took the blood sample it would look opaque - But if you are in a “fasted” state, then the blood plasma would look more clear and yellowish o The difference is that the opaque has chylomicrons which are made through fat digestion. These particles are large enough to deflect light and that is why blood has the opacity to it. **Chylomicrons are unique in that they are made in the intestine and are taken up from there. The other lipoproteins are made by the liver. VLDL = - very large density lipoprotein and is made in the liver and the protein that is put on it is Apo B-100 a different protein from Apo - B48 and it is very large and - VLDL is packaged with a lot of triglycerides . LDL = - a VLDL and has lost part of triglycerides and then is circulating in the bloodstream . HDL = - smallest lipoprotein and is mostly protein and has highest density and has some cholesterol esters and has the apoproteins A and D and some others. (good cholesterol) - The diagram is a model of a VLDL but it is a model for all lipoproteins . - Lipos are collections of lipids and proteins noncovalently collected together and packaged together so the surface contains phospholipids and have polar groups . - The phospholipids coat the surface and some cholesterol packs with the phospholipids, the center has triglycerides and cholesteryl esters . - They form oil in the middle of the lipos and the surface must have phospholipids since it has a polar, charged coat that make the surface to interact with water and the apoproteins depending on what kind it is (apoB100 is pictured) and others could have other relationships with the surface and interior depending on the apoprotein. Density
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/14/2011 for the course PHARM ERM taught by Professor Staff during the Spring '11 term at UCSD.

Page1 / 5

Lecture 14 - Lipoprotein Structure and Receptor Function -...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online