Lipids + Carbohydrates

Question 1

The role of proteins in viruses

Answer 1

• Defence and targeting of the genome
• Shape of virion
• Enzymes for multiplication
• Receptors

Question 2

Give the groupings of proteins of viruses

Answer 2

• Structural proteins
  
  • Surface proteins
  • Core proteins
• Non-structural proteins

Question 3

Surface proteins

Answer 3

• Capsid/Envelope
• Characteristics:
  
  • Shape
  • Antigenicity
  • Adsorption
  • HA activity
  • Enzymes for penetration/release of virions

Question 4

Core proteins

Answer 4

• Characteristics:
  
  • NA protection
  • Stabilisation
  • Enzymes for replication

Question 5

Non-structural proteins

Answer 5

• Coded in the viral genome
• Not integrated in the virion
• Only present in the vegetative virus
• Early proteins
• Late proteins

Question 6

Early proteins

Answer 6

• Regulation of the cell
• Inhibition of cellular defence
• Enzymes for replication

Question 7

Late proteins

Answer 7

Enzymes for structural protein maturation + virus assembly

Question 8

List the methods of protein investigation

Answer 8

• SDS-polyacrylamide-gel electrophoresis (PAGE)
• Immunoblotting
• Immunoperoxidase staining
• Monoclonal antibody production

Question 9

SDS-Polyacrylamide-gel electrophoresis (PAGE)

Answer 9

• Concentrated virus suspension
• • SDS + Mercapto-ethanol
    
    • → Linearisation
• Electrophoresis
• Staining
  
  • Polypeptide map
  • Characteristic of the virus
  • Number + size of viral polypeptides

Question 10

Immunoblotting

Answer 10

• Western blot
• Transfer of viral proteins from PAGE → Nitrocellulose filter

Question 11

Immunoperoxidase staining

Answer 11

SDS-PAGE, western blot or in histology sections

• Detection of antigens
• Diagnostics, identification
• Mechanism + timing of protein production
• Epitope investigation

Question 12

Immunoperoxidase staining:

Steps of detection of antigens

Answer 12

1. Cover with primary Ab
2. Incubation + washing
3. Cover with conjugate
4. Incubation + washing
5. Cover with substrate
6. Colour reaction

Question 13

Monoclonal antibody production steps

Answer 13

1. Monoclonal antibody: produced by a single clone of B cells
2. Specific for a particular epitope
3. Mouse immunisation with viral antigen
4. Isolation of lymphocytes from spleen
5. Mixing with myeloma cells (Mitosis, no Ab production)
6. Fusion of cells by polyethene glycol

Question 14

Title the figure

Answer 14

Monoclonal antibody production

Question 15

Answer 15

Immunised mice

Question 16

Answer 16

Remove spleen

Question 17

Answer 17

Cell fusion

Question 18

Answer 18

Myolema cells

Question 19

Answer 19

Expand cells in 48-well plates

Question 20

Answer 20

Grow cells in HAT media

Question 21

Answer 21

Check cells for production of antibodies

Question 22

Answer 22

ELISA

Question 23

Answer 23

Expand cells that tested positive into 96-well plates

Question 24

Answer 24

Production of monoclonal antibodies in mice or tissue culture

Question 25

Viral lipids

Answer 25

• Enveloped viruses (30-35%)
• Acquired from the cellular membrane structures
  
  • Phospholipid, cholesterol
  • Virus-specific glycoproteins
  • Virus-specific lipids → Pox, African swine fever

Question 26

Viral carbohydrates

Answer 26

• Ribose, deoxyribose
  
  • in the NA
• Glycoproteins
  
  • On the surface
  • Pox: in the core too