Genetic Engineering Multiple Choice Questions on “Fusion Proteins”.
1. There are some advantages of expressing protein as a fusion protein. It may enhance stability, folding ______ and ______ formation.
a) solubility, phosphodiester bond formation
b) insolubility, phosphodiester bond formation
c) solubility, disulphide bond formation
d) insolubility, disulphidebond formation
Answer: c
Explanation: Expressing a protein as a fusion protein is advantageous. It may enhance stability, folding, solubility and disulphide bond formation.
2. A short peptide region fused to a protein of interest is known as ___________
a) tag
b) oligonucleotide
c) fragment
d) dimer
Answer: a
Explanation: A short peptide region (generally, a few nucleotides long) is fused to a protein of interest and is known as tag.
3. Glutathione-S-Transferase (GST) enzyme is used for the conjunction of Glutathione molecules and is having a protective function in many organisms.
a) True
b) False
Answer: a
Explanation: GST enzyme is used for the conjunction of Glutathione molecules and is also having a protective function in many organisms. It is widely used as a basis for fusion proteins.
4. Maltose binding protein is the product of ______ gene in E.coli and located in ______
a) malE, nucleus
b) malD, nucleus
c) malE, periplasmic space
d) malD, periplasmic space
Answer: c
Explanation: Maltose binding protein is the product malE gene in E.coli and is located in the periplasmic space. It is responsible for uptake of maltose and other sugars.
5. Thioredexin protein contains two _______ residues.
a) cysteine
b) cystine
c) adenine
d) guanine
Answer: a
Explanation: This protein contains two cysteine residues and they are reversibly oxidized to cysteine residues.
6. Often, protein to be expressed is fused with histidine and it is called as histidine tags. For their purification, matrix containing ______ is used.
a) calcium ions
b) nickel ions
c) iron ions
d) fluorine ions
Answer: b
Explanation: Histidine tags are used in place of naturally occurring protein at times for fusion proteins. For purification, matrix containing nickel ions is used and is based on affinity purification.
7. Pel B protein is produced in plants and helps in the degradation of ______
a) vacuole
b) plasma membrane
c) cell wall
d) mitochondria
Answer: c
Explanation: Pectate lyase or pelB protein is produced in plants and helps in the degradation of plant cell wall.
8. His tagged proteins can be eluted using EDTA or a pH gradient from the matrix.
a) True
b) False
Answer: a
Explanation: His tagged proteins can be eluted using EDTA or a pH gradient from the matrix. They disrupt the chelation.
9. Enterokinase is an intestinal enzyme that converts _______ to ________
a) pepsinogen, pepsin
b) pepsin, pepsinogen
c) trypsinogen, trypsin
d) trypsin, trypsinogen
Answer: c
Explanation: Enterokinase is an intestinal enzyme which is used to convert inactive trypsinogen to trypsin. It forms the basis for the extraction of fusion proteins from the matrix.
10. Cyanogen bromide is used for cleavage of junctions. It cleaves after ________ residues.
a) methionine
b) tryptophan
c) cysteine
d) phenolic acid
Answer: a
Explanation: Cyanogen bromide is used for cleavage of junctions and it cleaves after methionine residues. But this method is not widely used.