IC7 & IC8

Question 1

Usual body protein size

Answer 1

6-8 kDa

Question 2

MW of proteins more than ____ may be eliminated via phagocytosis

Answer 2

200 kDa

Question 3

Intestinal epithelium generally carries_____ charges

Answer 3

negative

Question 4

Is convection affected by MW?

Answer 4

not affected by MW unless proteins are enormously large & gets trapped in ECM

Question 5

Convection may be influenced by _______

Answer 5

steric hindrance & charge interactions

Question 6

Larger proteins ____ move slowly across capillary membrane

Answer 6

> 16-20kDa

Question 7

Are proteins metabolised by liver?

Answer 7

No, they are poor CYP substrates. Mostly metabolised via proteolysis.

Question 8

Charge of glomerular basement membrane

Answer 8

Negative

Question 9

Which protein sizes cannot be renally eliminated?

Answer 9

Proteins > 50 kDa not eliminated renally

Question 10

Should vaccines be PEGlyated?

Answer 10

No, because we want immunogenicity

Question 11

Ways to incr protein half-life

Answer 11

1. Glycosylation of proteins
2. PEGylation
3. Incr size by means of fusion proteins

Question 12

Two pathways in which proteins are degraded in mammalian cells

Answer 12

1. Lysosomal pathway
2. Proteasomal pathway

Question 13

Normal levels of HIF-1alpha at normoxia

Answer 13

Low

Question 14

Under normoxic conditions, HIF-1alpha is hydroxylated by oxygen-dependent _______

Answer 14

prolylhydroxylases

Question 15

What happens to hydroxylated HIF-1alpha?

Answer 15

It gets recognized and targeted for ubiquitination

Question 16

Role of HIF-1 alpha

Answer 16

A transcription factor responsible for oxygen homeostasis during hypoxic conditions; induces expression of genes involved in angiogenesis, cell migration and glycolytic pathway

Question 17

Is lysosomal degradation a specific process?

Answer 17

No, as long as proteins are in lysosomes, regardless of identity, they are degraded.

(In higher eukaryotes, only membrane-associated proteins and alien proteins internalized by endocytosis are degraded in lysosomes.)

Question 18

Is proteasomal degradation a specific process?

Answer 18

Yes, it takes place for ubiquitinated or some non-ubiquitinated proteins.

Question 19

Is pinocytosis a specific process?

Answer 19

No

Question 20

Role of 26 proteasome

Answer 20

responsible for specific degradation of regulatory proteins and removal of damaged proteins

Question 21

Composition of 20s core structure of 26 proteasome

Answer 21

4 heptameric rings: 2 alpha outer subunits + 2 beta inner subunits

Question 22

Structure of 26 Proteasome

Answer 22

20S core particle capped by a 19S regulatory particle at one or both ends

Question 23

Inner rings of 26 proteasome house a central cavity containing ________

Answer 23

proteolytic active sites

Question 24

Ubiquitin tag cleaved by _________ into monomers.

Answer 24

deubiquitinating enzymes

Question 25

How many lysines do ubiquitin contain?

Answer 25

7 lysines

Question 26

Ubiquitin is almost always attached to substrate protein through an isopeptide bond between ______ of Ub and the ______ Lys in the substrate.

Answer 26

C-terminal Gly; amino group of

Question 27

Minimal signal necessary for proteasome targeting: a chain of ______ linked through _____

Answer 27

4 Ub monomers; Lys48

Question 28

mW of traditional chemical-based drugs

Answer 28

< 1000Da

Question 29

MW of biopharmaceutical products/ biologics

Answer 29

typically in kDa

Question 30

All biopharmaceutical products are protein-based (T/F).

Answer 30

False. Not all. Majority (>95%) of biopharmaceuticals are protein products.

Question 31

Definition of convection

Answer 31

Collective bulk movement of large mass of particles in a fluid (the flux is fluid- driven/driven by motion of the bulk fluid)

Question 32

2 transport mechanisms for proteins upon SC administration in the ECM

Answer 32

1. Diffusion 2. Convection

Question 33

Absorption for larger proteins > _____ kDa mostly occur through lymphatic system

Answer 33

16-20

Question 34

Smaller proteins < 16-20 kDa, absorption can be via both _________

Answer 34

circulatory and lymphatic systems

Question 35

Hypodermis is also known as ____

Answer 35

Subcutaneous tissue

Question 36

Rate limiting factors that can cause changes to absorption rates of proteins drugs after SC/IM administration

Answer 36

1. Interstitial fluid transport rate 2. Lymphatic transport rate

Question 37

Interstitial fluid refer to _____

Answer 37

Fluid embedding the ECM

Question 38

Role of FcRn

Answer 38

responsible for transport of maternal IgG (1) across placenta to foetus, and (2) from mother’s milk across intestines of newborn babies.

Question 39

FcRn name

Answer 39

Neonatal Fc receptor

Question 40

At ______, FcRn binds to Fc domain of IgG or albumin to form FcRn-IgG or FcRn-albumin complex.

Answer 40

acidic pH 5-6

Question 41

Charge of protein that allows it to have higher renal filtration

Answer 41

Positive charge (since glomerular basement mbm has neg charge)

Question 42

Protein charge that gets reabsorbed by renal tubules

Answer 42

Positive charge

Question 43

Factors affecting renal excretion of proteins

Answer 43

1. Charge of protein 2. MW of protein 3. Shape & rigidity of protein 4. Tubular reabsorption of protein

Question 44

2 ways in which proteins can be eliminated

Answer 44

1. Proteolytic degradation (extracellular and intracellular) 2. Renal (glomerular) filtration (dominates renal excretion of protein drugs)

Question 45

2 types of PEG

Answer 45

1. PEG with free hydroxyl at both ends 2. methoxylated PEG (mPEG) with hydroxyl at one or both ends methoxylated

Question 46

Substances fused to proteins to incr circulation half-life

Answer 46

1. Fc domain of antibody 2. Albumin

Question 47

Concern for fusion proteins with Fc domain of antibody

Answer 47

Fc domain may trigger unwanted effector functions -> trigger unwanted immune (inflammatory) responses

Question 48

Can a biosimilar biologic be entirely identical to the innovator biologic? Why?

Answer 48

No, due to variability of the biological expression system and manufacturing process

Question 49

sialylated glycans almost absent in Mabs produced in ______

Answer 49

CHO cells