Ch. 10 Recombinant Proteins

Question 1

Which of the following is a clinically relevant protein produced by recombinant technology?

Answer 1

All of the above

• insulin
• interferon
• factor VIII
• tissue plasminogen activator

Question 2

Which of the following is associated with translation efficiency for the mRNA of genes cloned for protein expression?

Answer 2

All of the above

• mRNA stability
• strength of the ribosomal binding site
• codon usage
• mRNA secondary structure

Question 3

Which of the following is NOT a feature of translational expression vectors?

Answer 3

The native promoter for the gene that is to be cloned into the vector

Question 4

Which method to overcome codon usage problems is the least labor-intensive?

Answer 4

Supply the genes for the rare tRNAs on a separate plasmid

Question 5

In expression systems, which of the following forms when too much protein is manufactured too quickly?

Answer 5

T7 RNA polymerase

Question 6

How can recombinant protein production be enhanced?

Answer 6

Co-expression of a molecular chaperone

Question 7

What can be done to ensure a recombinant protein is excreted outside the cell?

Answer 7

All of the above

• addition of a signal sequences
• using specialized export systems
• fusion to a protein that is normally exported
• expressing the protein in an alternative system, such as Gram-positive bacteria

Question 8

What could be used to increase the stability and purification of eukaryotic proteins from bacterial cells?

Answer 8

A peptide tag

Question 9

Why would it be necessary to express eukaryotic proteins in eukaryotic cells rather than in bacterial cells?

Answer 9

Protein production in eukaryotic cells never produces inclusion bodies, which sometimes form in bacterial cells due to overexpression

Question 10

Which of the following is not a problem associated with low yields of proteins expressed in yeast?

Answer 10

Proteins are not getting secreted into the medium

Question 11

What is a bacmid?

Answer 11

A shuttle vector that replicates as a plasmid in E. coli and a virus in insect cells

Question 12

Are insect cells fully able to glycosylate foreign proteins?

Answer 12

No

Question 13

Which of the following is not used as a selectable marker to maintain mammalian shuttle vectors within mammalian cells?

Answer 13

Glutamine synthetase gene

Question 14

What function does an internal ribosomal entry site serve?

Answer 14

As a protease cleavage site in between two proteins expressed in one transcript

Question 15

Which factor affects which protein expression system to utilize?

Answer 15

All of the above

• cost
• ability to glycosylate or fold proteins
• speed
• government regulations

Question 16

Which of the following is not involved in the manufacturing of insulin?

Answer 16

Phosphodiesterase 5

Question 17

Which of the following statements about insulin manufacturing is NOTes true?

Answer 17

Bacteria are able to express preproinsulin and process this peptide into insulin

Question 18

The recently discovered autotransporter proteins of bacteria:

Answer 18

Require the BAM complex to cross the bacterial outer membrane

Question 19

True about insulin manufacturing

Answer 19

• diabetics used to have to inject themselves with insulin that had been purified from the pancreas of either cows or pigs
• natural insulin forms hexagamers, which causes the hormone to clump
• a proline converted to an aspartic acid keeps insulin from clumping
• recombinant insulin is expressed as two mini-genes

Question 20

Features of translational expression vectors

Answer 20

• a selectable marker
• terminator sequences
• consensus RBS plus the ATG initiation codon
• a strong, but regulated, transcriptional promoter

Question 21

Inclusion bodies

Answer 21

dense crystals if misfolded and nonfunctional protein

Question 22

Joining the coding sequences of two proteins together in frame makes a ___ ___.

Answer 22

Protein fusion

Question 23

Type I secretory system -

Answer 23

Spans both inner and outer membranes and is used to secrete hemolysin by some E. coli strains that cause urinary infections

Question 24

Type II secretory system -

Answer 24

Spans the outer membrane only

Question 25

__ is required for proper biological function of many proteins.

Answer 25

Glycosylation

Question 26

Polyhedrons -

Answer 26

Baculoviruses form in packages of virus particles

Question 27

Polyhedrin -

Answer 27

Matrix protein