1. LIPOPROTEIN AND
CHOLESTEROL
Angel Das
1 year MBBS Student

2. LIPOPROTEIN
Lipid
Lipoprotein
Protein

3. Structure of lipoprotein
INTEGRAL APOPROTEINS
CHOLESTEROL
ESTERS
MONOLAYER OF
PHOSPHOLIPID
AND CHOLESTERLOL
CORE
TRIGLYCERIDES
PERIPHERAL APOPROTEINS

4. APOPROTEINS
Protein component of lipoprotein
Promote transport and uptake of
lipids
Act as ligand
Activation of enzymes

5. APOPROTEINS
A
B
• A-l
• A-ll
• B-48
• B-100
• A-I
Liver&
intestine
• A-II
Liver
• B-48
• B-100
C
E
• C-l
• C-ll
• C-lll
Intestine
Liver
• All Liver
• Liver

6. LIPOPROTEINS
Lipoprotein
Apoproteins
Chylomicron
A,B,C,E
VLDL
B,C,E
LDL
B
HDL
A,C,D, E

7. CLASSIFICATION
Based on density by ultracentrifugation
i. Chylomicrons
ii. Very Low Density Lipoprotein
iii.Intermediate Density Lipoprotein
iv.Low Density Lipoprotein
v. High Density Lipoprotein

8. COMPOSITION AND SIZE OF
LIPOPROTEIN

9. FUNCTIONS OF LIPOPROTEINS
CHYLOMICRONS
transport Triglycerides from intestine to adipose
tissues for storage.
VLDL
carries triglycerols from liver to peripheral tissues.

10. LDL
transports cholesterol from liver to peripheral tissues.
HDL
transports cholesterol from peripheral tissues to liver
“Reverse Cholesterol Transport”

11. CLINICAL SIGNIFICANCE
HYPERLIPIDEMIAS
elevated lipid fraction
cholesterol/TAG
Frederickson’s Classification
 Type l
 Type ll A
 Type ll B
 Type lll
 Type lV
 Type V

12. Type
Lipoprotein Metabolic
fraction
Defect
elevated
Type ll A (Primary
LDL
Familial
Hypercholesterolemia)
LDL receptor
defect
Type ll B
Hyperlipoproteinemia
LDL & VLDL
Apo B
Type lV Familial
endogenous Type
VLDL
Overproduction
of VLDL

13.  HYPOLIPOPROTEINEMIAS
i. Abetalipoproteinemia
microsomal triglyceride transfer protein is defective
LDL & VLDL decreases
ii. Hypo alpha lipoproteinemia
HDL level decreases
iii. Tangier Disease
absence of ATP binding Cassette Transporter 1, involved in
transport of cellular cholesterol to HDL

14.  ATHEROSCLEROSIS
• Deposition of LDL cholesterol in arterial wall, occurs
due to damage of endothelium

15. CHOLESTEROL
Physical Properties
white crystalline solid substance
soluble in ether,chloroform etc.
amphipathic in nature
abundantly present in nervous tissue
•Have

16. STRUCTURE OF CHOLESTEROL

17. FUNCTIONS OF
CHOLESTEROL
1. Major structural constituent of the cell membranes and lipoproteins
2. Precursor for Steroid hormones
a. Progesterons
b. Glucocorticoids
c. Mineralocorticoids
d. Androgens & Estrogens
3. Formation of Bile acids and bile salts.
4. Synthesis of Vitamin D