BME 6210 FINAL EXAM WITH
COMPLETE SOLUTION
Challenges with proteins as therapeutics - ANSWER 1. immune response
2. short half life of circulation
solutions for proteins as therapeutics - ANSWER 1. change AA sequence
2. piggyback on circulating proteins
3. encapsulate in matrix (PLGA)
4. hide protein with H20 soluble polymer (PEG)
design criteria for PEGylation - ANSWER 1. # of PEGs attached (too few = no
effect, too many = decreased bioactivity)
2. M.W. (too short = no effect, too long = no clearance)
3. site of attachment (not active site)
4. attachment chemistry
3 PEG conjugation methods - ANSWER 1. NH2 of lysine
2. Cystine
3. N-terminus
problem with NH2 of lysine conjugation and solution - ANSWER reaction
occurs very quickly --> control by adding hydrophobicity or steric bulk
problem with cystine conjugation - ANSWER if one S in S-S bond binds SH
, --> destabilizes whole protein
3 types of cystine conjugation - ANSWER 1. maleimide
2. vinyl sulfone
3. orthopyridyl disulfide
N-terminus conjugation reaction - ANSWER PEG-hemi-acetal --> change pH
--> PEG-aldehyde + protein-NH2 --> unstable imine --> reduce --> 2* amine
problems with nucleic acid therapeutics - ANSWER 1. chemically and
biologically unstable
2. high M.W.
3. negatively charged
--> won't passively permeate cell
4 types of nucleic acid delivery - ANSWER 1. antisense oligonucleotides
2. plasmid DNA
3. short interfering RNA
4. mRNA
how does antisense oligonucleotide based delivery work? - ANSWER 10-20
base antisense oligonucleotide binds to complementary mRNA --> antisense
is recognized by RNAase H b/c it doesn't belong --> RNAase H cleaves
hybridized mRNA --> ribosome won't make protein
result: decreased expression of target protein
how does plasmid DNA based delivery work? - ANSWER gene of interest
COMPLETE SOLUTION
Challenges with proteins as therapeutics - ANSWER 1. immune response
2. short half life of circulation
solutions for proteins as therapeutics - ANSWER 1. change AA sequence
2. piggyback on circulating proteins
3. encapsulate in matrix (PLGA)
4. hide protein with H20 soluble polymer (PEG)
design criteria for PEGylation - ANSWER 1. # of PEGs attached (too few = no
effect, too many = decreased bioactivity)
2. M.W. (too short = no effect, too long = no clearance)
3. site of attachment (not active site)
4. attachment chemistry
3 PEG conjugation methods - ANSWER 1. NH2 of lysine
2. Cystine
3. N-terminus
problem with NH2 of lysine conjugation and solution - ANSWER reaction
occurs very quickly --> control by adding hydrophobicity or steric bulk
problem with cystine conjugation - ANSWER if one S in S-S bond binds SH
, --> destabilizes whole protein
3 types of cystine conjugation - ANSWER 1. maleimide
2. vinyl sulfone
3. orthopyridyl disulfide
N-terminus conjugation reaction - ANSWER PEG-hemi-acetal --> change pH
--> PEG-aldehyde + protein-NH2 --> unstable imine --> reduce --> 2* amine
problems with nucleic acid therapeutics - ANSWER 1. chemically and
biologically unstable
2. high M.W.
3. negatively charged
--> won't passively permeate cell
4 types of nucleic acid delivery - ANSWER 1. antisense oligonucleotides
2. plasmid DNA
3. short interfering RNA
4. mRNA
how does antisense oligonucleotide based delivery work? - ANSWER 10-20
base antisense oligonucleotide binds to complementary mRNA --> antisense
is recognized by RNAase H b/c it doesn't belong --> RNAase H cleaves
hybridized mRNA --> ribosome won't make protein
result: decreased expression of target protein
how does plasmid DNA based delivery work? - ANSWER gene of interest
