This document discusses plasma proteins and the differences between blood, plasma, and serum. It outlines the major plasma proteins including albumin, globulins, fibrinogen, transport proteins, immunoglobulins, and clotting factors. Albumin is the most abundant plasma protein and serves important functions like maintaining osmotic pressure and transporting substances through the bloodstream. Globulins include alpha-1 proteins, alpha-2 proteins, and beta and gamma globulins which are involved in processes like iron transport, protease inhibition, and immunity. Acute phase proteins either increase or decrease during inflammatory responses.

1. PLASMA PROTEINS-II
Prof. Dr. Viyatprajna Acharya

2. BLOOD
PLASMA
SERUM
WHAT’STHE DIFFERENCE?

3. Total blood volume: 4.5-5 lit
Whole blood left to clot centrifuged
Supernatant is ‘SERUM’
Blood+ Anticoagulant centrifuged
Supernatant is ‘PLASMA’
55-60% of BLOOD- PLASMA
Defibrinated plasma = Serum

4.  Total plasma protein content- 6-8 gm/dl
 Hundreds of different proteins in plasma
 Important ones:
Albumin
Globulin
Fibrinogen
Clotting factors
Transferrin
Ceruloplasmin; etc

5. Albumin- 3.5-5 gm/dl
Globulin- 2.5-3.5 gm/dl
Fibrinogen- 200- 400 mg/dl
A: G ratio – 1.2:1 to 1.5: 1
Almost all proteins except Immunoglobulins
synthesized in liver

6. Comparisonofsizes

7. Around300plasmaproteins
Important ones:
1. Albumin
2. Globulin
3. Fibrinogen
4.Transport proteins
5. Immunoglobulins
6. Clotting factors
7. Acute phase proteins

10. Most abundant in plasma
Found in extra-vascular fluids
One polypeptide chain
585 AA; 17 disulfide bonds
Synthesized by hepatocytes
12g/day produced
T1/2 is 15-19 days
Over 80 allelic forms available

11. Functionsofalbumin
Exerts osmotic pressure- effective osmotic pressure
(25mm Hg)
80% exerted by albumin
Transport- Bilirubin
NEFA
Drugs
Steroid hormones
Calcium
Copper
Heavy metals

12. Buffering action- 16 His residues
Nutritional function-contributes to essential AA
pool

13. Clinicalsignificance
HYPERALBUMINEMIA: Rare and insignificant;
Dehydration
HYPOALBUMINEMIA:
Cirrhosis of liver
Malnutrition
Acute inflammation
Burns
Nephrotic syndrome
Albuminuria
Protein losing enteropathy
ANALBUMINEMIA: rare genetic defect; albumin<
0.5g/dl; mild edema

14. Pre-albumin
 Minor band running ahead of Albumin
 TBPA (Thyroxin binding prealbumin)
 RBPA(Retinol binding prealbumin)
 Low levels: Hepatitis
Early cirrhosis
Thyrotoxicosis
Deficiency of Zn

15. Globulins

16. Alpha 1 Proteins
 Alpha-1-Lipoprotein-HDL
 Alpha-1-Antitrypsin
-- Protease inhibitor(Particularly Elastase) that
binds to and inactivates trypsin
– Deficiency leads to destruction of the alveolar
walls and is associated with pulmonary
deficiency- Emphysema
– Deficiency also seen in cirrhosis
– Alpha-1-antitrypsin is an acute phase protein and
is increased in acute episodes of tissue damage

17.  α1-Acid glycoprotein (orosomucoid) -
 45% carbohydrate
 Synthesized by hepatocytes
 Binds and inactivates lipophilic and basic
hormones e.g. Progesterone
 Acute phase protein
 ↑ levels- pregnancy, ulcerative colitis
• α1-Fetoprotein (AFP)
 Principal foetal protein, used to screen for foetal
abnormalities (neural tube defects)
 Tumor marker for hepatocellular and germ cell
carcinomas
 ↓levels- fetal trisomy 18 or 21

18. α2 Globulins
 Ceruloplasmin
 Cu containing
 6-8 Cu per molecule
 Regulation of oxidation-reductions, transport
and utilization of iron
 ↓level- Wilson’s hepatolenticular degeneration

19.  Transcortin/ Corticosteroid binding
globulin- Binds cortisol
↑ synthesis by estrogen
 Haptoglobin- Conservation of iron
 Thyroxin binding globulin- TransportsT3
&T4
 α2 Macroglobulin- natural inhibitor of
endopeptidase such as trypsin, chymotrypsin,
plasmin, thrombin- in vivo anticoagulant
- ↑level- Nephrotic syndrome, cirrhosis, collagen
disorder
- ↓ level- Myeloma, peptic ulcer

20. β-Globulin
 Haemopexin- Binds to free heme and
conserves
 Transferrin-Transports iron
↑ level- Fe deficiency anemia, Pregnancy
↓ level- Chr. Infections, malnutrition
 β2- Microglobulin- part of HLA
↑level- malignant lymphoid or myeloid
proliferation , Renal failure

21.  C-reactive protein (CRP)- reacts with c-
polysaccharide of cell wall of pneumococci
- ↑level- bacterial infections
-hs-CRP- predicts the risk of coronary disease

22. γ-Globulins
 Immunoglobulins - 5 major classes

23. Acutephaseresponse&acutephaseproteins
 Non-specific response to the stimulus of tissue
following trauma, infection, inflammation and
burn etc.– ACUTE PHASE RESPONSE
 ACUTE PHASE PROTEINS-- ↑ levels within few
hours of assault
CRP
Ceruloplasmin
α1 Antitrypsin
α1 acid glycoprotein
Haptoglobin
Fibrinogen etc.

24. NEGATIVEACUTEPHASEREACTANTS/
PROTEINS
 ↓ level in inflammatory processes
Albumin
Prealbumin
Retinol binding protein
Transferrin

25. After silence, that which comes nearest to expressing the inexpressible is music.
Aldous Huxley