3. Lipids compounds:
Relatively water insoluble
Digestion: after Emulsifiction
Absorption: as Micelles
Blood transport: as Lipoproteins
Introduction
9. ecretion of Chylomicron from Intestin
Fat-Soluble vitamins
Microsomal TAG-transfer protein & assembly of CM in ER
10. Intestinal Apo B-48
Post-transcriptional editing of Apo B gene
Deamination of cytosine to uracil
Insertion of stop codon (Nonsense)
Translation of only 48% of Apo B gene
12. Lipoprotein Lipase
Synthesis: Adipocytes and muscle cells
Extracellular enzymes (isomer forms)
Anchored by HS to capillary walls
Most tissues, but not adult liver
Activated by: Apo C-II & Heparin
Deficiency: Type 1 hyperlipoproteinemia
13. Lipoprotein Lipase
Insulin: Synthesis & transfer
Isomer forms: Different Km
(Adipose :Large, But, Heart: Small)
Highest concentration: Cardiac muscle
Plasma clearing effect: Heparin
CONT’D
19. Lipoprotein (a) or
LP(a)
LP(a): ~ identical to LDL
Apo(a): Additional apoprotein
covalently-linked to apo B-100
Homologous to plasminogen
Interferes with breakdown of blood clots
& triggers heart attack
LP(a) plasma level: Risk for CHD
21. Lipoprotein-related Diseases
(A) Hyperlipoproteinemia
Type I Hyperlipoproteinemia
Familial Lipoprotein lipase deficiency
Type IIa Hyperlipoproteinemia
Familial hypercholestrolemia
Functional defect of LDL-receptor
Type III Hyperlipoproteinemia
Familial dysbetalipoproteinemia
Apo E-2 isoform
Hypercholestrolemia & atherosclerosis
22. Lipoprotein-related Diseases
(B) Hypolipoproteinemia
Congenital abetalipoproteinemia
Defect in TAG-transfer protein
Inability to load Apo B with lipids
No CM or VLDL formation
TAG accumulation: intestine & liver
(C) Fatty Liver (hepatic steatosis)
Decreased secretion of VLDL
Obesity, DM, Chronic alcoholism