Final - Schneebeli

Question 1

Peptide

Answer 1

A chain of amino acids (typically less than 40-50 amino acids)

Question 2

Protein

Answer 2

Longer amino acid chain with secondary structure (longer than 40-50 amino acids)

Question 3

From spheres to chemical structures

Answer 3

Semaglutide (Ozempic)
-Big vs small molecule drug
PEPTIDE BOND

Question 4

Semaglutide (Ozempic)

Answer 4

Synthetic peptide
31 Amino acids (peptide, not protein)
Weight loss drug

Question 5

All antibodies are

Answer 5

Proteins

Question 6

Peptide drugs can be produced with

Answer 6

Solid-phase synthesis

Question 7

Key challenge with nonenzymatic peptide synthesis

Answer 7

Coupling yields need to be extremely high, for a long linear synthesis
-Yields for consecutive reactions need to be multiplied

Question 8

Q: What would the overall yield be when synthesizing a linear peptide with 31 amino acid residues, and a yield of 90% for each coupling step?

Answer 8

0.038
-3.8% yield - this would only give 3.8% yield = VERY LOW = NOT GOOD

Question 9

Proteins depend on the length of the Peptide chain

Answer 9

Protein is any alpha amino acid polymer with a specific sequence that is greater than 40 amino acids in size

Question 10

Example of a protein

Answer 10

Insulin
51 AAs
Need to count both chains

Question 11

Compounding of _ is NOT allowed

Answer 11

Biologics
-Biological products are not eligible for the exemptions for compounded drugs under federal law
Biologics are very fragile - dangerous to do too much with them

Question 12

Protein drugs

Answer 12

Over 1,000 amino acids in length
Cannot be synthesized chemically
Highly complex and fragile drugs

Question 13

How are protein drugs produced

Answer 13

Produced by biosynthesis
Much more complex than small molecule drugs
100 to 1.00 liters
(mobile) pilot plant
probes for
-pH
-Dissolved O2
-Temperature
pressure
biomass
carbon source

Question 14

Ribosomal synthesis to post-translational modification

Answer 14

All controlled by the ribosome
-Takes messenger RNA and converts and uses as a template for proteins
know post-translational modifications

Question 15

Post-translational modifications

Answer 15

Disulfide bond
Hydroxylation
Ubiquination
Lipidation
SUMOylation
Phosphorylation
Acetylation
Methylation
Glycosylation

Question 16

Comparison of different expression systems

Answer 16

Bacteria
-no glycosylation, endotoxins

Yeasts
-Glycosylation is limited, or proteins are hyperglycosylated

Insect cells
-Extensive glycosylation, no sialytransferase, insect specific glycans

Mammalian cells
CHO etc (expensive susceptible to contamination with human pathogens or oncogenes)
for antibodies, people usually go with this

Transgenic animals
-Expensive, susceptible to contamination with animal pathogens

Transgenic plants
-Inexpensive, no contamination with animal pathogens, glycosylation

Question 17

Posttranslational Modifications (PTMs) - Primary Difference Between Biosimilars

Answer 17

Target DNA, express it, different PTMs
-Similar, but not the same (different sugars)
-Might get the same protein sequence, but never 100% the same (NOT a generic)

Question 18

Even a small difference in _ can lead to serious issues

Answer 18

Glycosylation
Ex. - Immune response

Question 19

Conditions that can lead to protein degradation

Answer 19

High temp
Freeze-thaw
Agitation
Low pH
High pH
Forced deamidation
Oxidation
Photostability

Question 20

Agitation can lead to

Answer 20

Increased contact with surfaces, which in turn leads to aggregation
DO NOT SHAKE

Question 21

Why not to freeze biologics

Answer 21

Ice crystals form = more concentration = more aggregation

Question 22

T/F: Aggregation can happen a while after the aggregate forming event occurs

Answer 22

True
Happens much later, and very rapidly

Question 23

Native state

Answer 23

Folded state
Drug we want
Smaller surface area

Question 24

Unfolded state

Answer 24

Enhances aggregation
No longer has function
Can lead to immune response
Undesirable
LARGER surface area

Question 25

Which Gibbs is preferred, higher or lower?

Answer 25

LOWER - native

Question 26

In preferential exclusion: Excipients are _ from protein surface

Answer 26

Repelled

Question 27

More dimer formation leads to

Answer 27

More aggregation

Question 28

Why do we not compound biologics

Answer 28

Unpredictable; dimer formation happens at different concentrations for different proteins = leads to aggregation

Question 29

Nature can store proteins for a very long time in

Answer 29

Sugar glasses (Trehalose)
-Biomimicry (stabilize)

Question 30

Levemir

Answer 30

Long lasting insulin
Hydrophobic tail attached to insulin binds to albumin which extends the half-life
T1/2: 5-7hrs
98% of the drug is bound to albumin

Question 31

Semaglutide

Answer 31

LONG hydrophobic tail
Also binds to albumin
General strategy
t1/2: 7 days