Recombinant Protein Production

Question 1

Human insulin

Answer 1

A polypeptide hormone that regulates fuel metabolism and whose administration is required for survival by certain types of diabetes.

Question 2

Human growth hormone

Answer 2

Somatotropin-induces the proliferation of muscle, bone, and cartilage and is used to stimulate growth in children of abnormally short stature

Question 3

Erythropoietin

Answer 3

A protein growth factor secreted by the kidney that stimulates the production of RBCs & is used in the treatment of anemia arising from kidney disease

Question 4

Colony-stimulating factors

Answer 4

Stimulate the production & activation of the white blood cells and are used clinically to counter the white cell-killing effects of chemotherapy and to facilitate bone marrow transplantation

Question 5

Tissue-type plasminogen activator

Answer 5

(tPA) which is used to promote the dissolution of the blood clots responsible for heart attacks and stroke

Question 6

Hepatitis B

Answer 6

Synthetic vaccines consisting of harmless but immunogenic components of pathogens

Question 7

Site-directed mutagenesis

Answer 7

An oligonucleotide containing a short gene segment with the desired altered base sequence corresponding to the new amino acid sequence is used as a primer in the DNA polymerase I mediated replication of the gene of interest. Such a primer can be made to hybridize to he corresponding wild-type sequence if there are only a few mismatched base pairs, and its extension, by DNA polymerase I, yields the desired altered gene

Question 8

Monoclonal antibodies

Answer 8

A single species of antibody produced by a clone of an antibody-producing cell; can be targeted against specific proteins and hence are used as antitumor agents

Question 9

Trastuzumab

Answer 9

Monoclonal antibody (trade name Herceptin), which binds specifically to the growth factor receptor HER2 that is overexpressed in ~25% of breast cancers, blocks HER2’s growth-signaling activity, thereby causing the tumor to stop growing or even regress

Question 10

Cassette mutagenesis

Answer 10

Complementary oligonucleotides containing the mutation (s) of interest are chemically synthesized and annealed to create a duplex “cassette”. The cassette is then ligated into the target gene, which must therefore contain an appropriately placed unique restriction site (which can be introduced through site-directed mutagenesis; the cassette must, of course, have the corresponding sticky ends)

Question 11

Allotransplantation

Answer 11

Transplantation between humans of organs such as hearts, lungs, livers, and kidneys

Question 12

Xenotransplantation

Answer 12

Process in which transplant is procured from animal to human (Ex. pig organ into human), which is triggered by the foreign antigens lining the blood vessels of the xenograft (the complement system constitutes the body’s first line of immunological defenses). The hyper-acute rejection occurs because the porcine tissue lacks the human proteins that inhibit the human complement system.

Question 13

Severe combined immunodeficiency disease (SCID)

Answer 13

Any of several genetic diseases that so impair the immune system that a victim must be kept in a sterile environment in order to survive.

Question 14

Liposomes

Answer 14

Membrane enveloped vesicles that are designed to be taken up by specific cells

Question 15

Cystic Fibrosis

Answer 15

One of the most common genetic diseases, is caused by a defect in a protein involved in the secretion of chloride ion in the lungs and other tissues. This causes the secretion of abnormally thick mucus, which results in recurrent and often damaging lung infections leading to early death.

Question 16

SCID-X1

Answer 16

Which is caused by a mutation in the gene encoding the yc cytokine receptor, a receptor for certain protein growth, and survival of the white blood cells known as T cells
-The viral vector containing the yc cytokine receptor gene integrates into the genome at random, the location of the transgene may affect the expression of other genes, triggering cancer

Question 17

Tay Sachs disease

Answer 17

Caused by the absence of the lysosomal enzyme hexosaminidase A and results in progressive neuronal dysfunction that is invariably fatal by around age 3.

Question 18

Lysis

Answer 18

Breaking open of a cell (Context: If the protein of interest is located in the cytosol of the cell, its liberation requires only the breaking open of the cell)-Osmotic lysis, the cells are suspended in a hypotonic solution (a solution in which the total molar concentration of solutes is less than that inside the cell in its normal physiological state)

Question 19

Differential centrifugation

Answer 19

A process in which the cell lysate is centrifuged at a speed that removes only the cell components denser than the desired organelle followed by centrifugation at a speed that spins down the component of interest.

Question 20

Proteases

Answer 20

Enzymes that catalyze the hydrolytic cleavage of peptide bonds. Care must be taken that the protein is not damaged by these enzymes.
-Many proteins are denatured by contact with the air-water interface and, at low concentrations, a significant fraction of the protein present may be lost by adsorption to surfaces

Question 21

Coupled enzymatic reaction

Answer 21

The product of the enzyme being assayed is converted, by an added enzyme, to an observable substance.

Question 22

Antibodies

Answer 22

Proteins that are produced by an animal’s immune system in response to the introduction of a foreign protein and that specifically bind to the foreign protein

Question 23

Radioimmunoassay

Answer 23

A protein can be indirectly detected by determining the degree with which it competes with a radioactively labeled standard for binding to the antibody

Question 24

An enzyme-linked immunosorbent assay (ELISA)

Answer 24

1. An antibody against the protein of interest is immobilized on an inert solid such as polystyrene
2. The solution being assayed for the protein is applied to the antibody-coated surface under conditions in which the antibody binds the protein. The unbound protein is then washed away.
3. The resulting protein-antibody complex is further reacted with a second protein-specific antibody to which an easily assayed enzyme has been covalently linked.
4. After washing away any unbound antibody-linked enzyme, the enzyme in the immobilized antibody-protein-antibody-enzyme in the immobilized antibody-protein-antibody-enzyme complex is assayed, thereby indicating the amount of the protein present.

Question 25

Chorionic gonadotropin

Answer 25

Placental hormone

Question 26

Elution

Answer 26

Those proteins with relatively low affinities for the ion exchanger move through the column faster than the proteins that bind to the ion exchanger with higher affinities.

Question 27

Ion exchange chromatography

Answer 27

The affinity with which a particular polyelectrolyte binds to a given ion exchanger depends on the identities and concentrations of the other ions in solution because of the competition of the other ions in the solution because of the competition among these various ions for the binding sites on the ion exchanger.

Question 28

Dextran

Answer 28

A high molecular mass polymer of glucose produced by the bacterium-Leuconostoc mesenteroides

Question 29

Agarose

Answer 29

A linear polymer of alternating D-galactose and 3,6-anhydro-L-galactose from red algae.