MOLECULAR BIOLOGY

1. MOLECULAR BIOLOGY
PROTAMINES
SUBMITTED BY:
S.DHASARADHA BAI
18PBI803

2. INTRODUCTION
 Protamines are small , arginine – rich nuclear proteins
that replace histones in the later haploid phase of
spermatogenesis
 They are essential for sperm head condensation and
DNA stabilization
 PRM – 1 and PRM – 2 are available as examples
 Salmine in salmon fishes, clupeine in herring sperm and
iridine in rainbow trout are other examples

3. HISTORY
Protamine was originally isolated from the sperm of
salmon
 Nowadays, it is produced through recombinant
technology
PROTAMINE SULPHATE:
 It is a medication used to reverse the effects of heparin
 Specifically, it is given for heparin overdose and is
given as injection into the vein

6. PROTAMINE STRUCTURE
 The primary structure consists of P1 used for packing DNA in
sperm cells
 It has 3 domains – arginine rich domain which plays a very
important role
 After translation P1 is phosphorylated. Another phosphorylation
occurs when the sperm enters the egg
 P1 binds to DNA and cysteine from the amino terminal of one P1
forms disulphide bond with the cysteine from the carboxy
terminal of another P1
 The disulphide bond prevents the dissociation of P1 from DNA
until the bonds are reduced when the sperm enters the egg
 The secondary and tertiary structures of protamines are not
known with certainity

7. PROTAMINES IN SPERMATOGENESIS
 Protamine binds to the phosphate backbone of DNA, urgently
binding with the arginine – rich domain as an anchor
 DNA is then folded into a toroid structure
 A sperm contains 50000 toroids in its nucleus and each toroid
weighs 50Kb
 Histones are removed from the DNA by transition nuclear
proteins so that protamines condense it
 The ratio of protamine 2 to protamine 1 and transition nuclear
proteins has been found to change the sperm head shape

8. DOSAGE - Dosage for heparin reversal is 1.0 to
1.5 mg.
Protamine sulphate IV for every 100 IU of active
heparin

9. MEDICAL USES
 When mixed with insulin, protamines slows down the
onset and increase the duration of insulin action
 Protamine sulphate is an antidote for heparin overdose
 It is used in cardiac surgery, interventional radiology
 It is used in gene therapy
 It is used as a drug to prevent obesity

10. ADVERSE EFFECTS
 Low blood pressure
 Slow heart rate
 Allergic reactions
 Nausea and vomiting
 Anaphylaxis
 Hypotension

11. REFERENCES :
 http://69i57j69i60j69i59l2j69i61j69i59.4https://www.go
ogle.co.in/search?q=PROTAMINES&oq=PRO&aqs=ch
rome.2.172j0j8&sourceid=chrome&ie=UTF-8
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC237501
4/
 https://www.sciencedirect.com/science/article/pii/S2305
050016300914
 MOLECULAR BIOLOGY – PRAGYA KHANNA

12. THANK YOU