Concepts of protein engineering MCQs With Answer

Concepts of protein engineering MCQs With Answer

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Concepts of protein engineering MCQs With Answer is a focused study aid tailored for M.Pharm students studying Proteins and Protein Formulations. This collection emphasizes core principles of protein engineering—rational design, directed evolution, stability and activity optimization, expression strategies, and formulation-related modifications such as PEGylation and glycoengineering. Each question targets practical understanding needed for drug development, biopharmaceutical design, and formulation science, linking theoretical concepts to laboratory techniques and computational tools commonly used in industry and research. Review these MCQs to strengthen problem-solving skills, prepare for exams, and gain a deeper appreciation of how engineered proteins are optimized for therapeutic performance, safety, and manufacturability.

Q1. What is the primary goal of protein engineering in the context of biopharmaceutical development?

  • To sequence a protein using mass spectrometry
  • To design and modify proteins to improve function, stability, or pharmacokinetic properties
  • To determine primary amino acid sequence only
  • To convert proteins into small molecule drugs

Correct Answer: To design and modify proteins to improve function, stability, or pharmacokinetic properties

Q2. Which two broad approaches are most commonly used in protein engineering?

  • Recombinant expression and chemical synthesis
  • Rational design and directed evolution
  • Mass spectrometry and X-ray crystallography
  • Solid-phase synthesis and peptide mapping

Correct Answer: Rational design and directed evolution

Q3. Site-directed mutagenesis is primarily used to:

  • Randomly generate large libraries of variants
  • Introduce specific amino acid substitutions at defined positions
  • Measure thermal stability of proteins
  • Determine glycosylation patterns

Correct Answer: Introduce specific amino acid substitutions at defined positions

Q4. Directed evolution typically involves which sequence of steps?

  • Structure determination → docking → synthesis
  • Mutagenesis → selection or screening → diversification → iterative cycles
  • Purification → mass spectrometry → sequencing
  • In silico design → single-step transformation

Correct Answer: Mutagenesis → selection or screening → diversification → iterative cycles

Q5. Which computational tool is widely used for predicting the effects of mutations on protein stability and designing mutations?

  • BLAST
  • Rosetta
  • Excel
  • PCR

Correct Answer: Rosetta

Q6. What is the main therapeutic advantage of PEGylation of a protein drug?

  • Increases enzymatic activity by altering active site geometry
  • Improves serum half-life and can reduce immunogenicity
  • Creates additional glycosylation sites
  • Makes the protein fluorescent for imaging

Correct Answer: Improves serum half-life and can reduce immunogenicity

Q7. Codon optimization for heterologous expression primarily aims to:

  • Alter the protein’s tertiary structure
  • Improve translation efficiency in the expression host
  • Increase the number of disulfide bonds
  • Remove post-translational modifications

Correct Answer: Improve translation efficiency in the expression host

Q8. Disulfide bond engineering is typically used to:

  • Decrease molecular weight of proteins
  • Enhance thermostability by introducing covalent crosslinks
  • Remove glycosylation heterogeneity
  • Replace aromatic residues with aliphatic residues

Correct Answer: Enhance thermostability by introducing covalent crosslinks

Q9. Which biophysical technique is most commonly used to determine real-time binding kinetics (kon/koff) between a protein and its ligand?

  • SDS-PAGE
  • Surface plasmon resonance (SPR)
  • UV-Vis absorbance
  • Isoelectric focusing

Correct Answer: Surface plasmon resonance (SPR)

Q10. Glycoengineering of therapeutic proteins is performed mainly to:

  • Reduce solubility in aqueous formulations
  • Alter pharmacokinetics, efficacy, and immunogenicity via glycan modification
  • Ensure proteins lack any post-translational modifications
  • Convert proteins into nucleic acids

Correct Answer: Alter pharmacokinetics, efficacy, and immunogenicity via glycan modification

Q11. Which high-throughput screening method is suitable for selecting protein binders from large libraries displayed on cells or phage?

  • Flash chromatography
  • Flow cytometry/FACS
  • Gel filtration chromatography
  • Western blotting

Correct Answer: Flow cytometry/FACS

Q12. For producing a therapeutic protein with human-like complex glycosylation, which expression system is most appropriate?

  • Escherichia coli
  • CHO (Chinese hamster ovary) mammalian cells
  • Saccharomyces cerevisiae
  • Cell-free E. coli lysate systems

Correct Answer: CHO (Chinese hamster ovary) mammalian cells

Q13. Deimmunization of a therapeutic protein refers to:

  • Increasing enzymatic turnover to reduce dosing
  • Reducing predicted T‑cell epitopes by sequence modification
  • Adding recognition sequences for proteases
  • Labeling the protein with radioactive isotopes

Correct Answer: Reducing predicted T‑cell epitopes by sequence modification

Q14. Which measurable parameter typically increases when a protein’s thermal stability is improved through engineering?

  • Isoelectric point (pI)
  • Melting temperature (Tm)
  • Extinction coefficient at 280 nm
  • Monomer molecular weight

Correct Answer: Melting temperature (Tm)

Q15. Which of the following is NOT a method used to create genetic diversity for library generation in directed evolution?

  • Error-prone PCR
  • DNA shuffling (recombination)
  • Saturation mutagenesis
  • SDS-PAGE analysis

Correct Answer: SDS-PAGE analysis

Q16. Which computational approach builds a 3D model of a target protein using experimentally solved structures of related proteins?

  • Ab initio folding
  • Homology (comparative) modeling
  • Principal component analysis
  • Fourier transform

Correct Answer: Homology (comparative) modeling

Q17. To alter an enzyme’s substrate specificity most effectively, engineering efforts should focus on:

  • Changing signal peptide sequences
  • Altering residues in and around the active site (substrate-binding pocket)
  • Modifying the C-terminal purification tag
  • Increasing overall protein glycosylation uniformly

Correct Answer: Altering residues in and around the active site (substrate-binding pocket)

Q18. What is a primary advantage of immobilizing enzymes on solid supports for biocatalysis?

  • Guaranteed increase in intrinsic catalytic rate constant (kcat)
  • Enables enzyme reuse and often improves operational stability
  • Removes the need for cofactors entirely
  • Converts enzymes into small molecules

Correct Answer: Enables enzyme reuse and often improves operational stability

Q19. Fusion of a therapeutic protein to an Fc domain commonly increases half-life by:

  • Creating new protease cleavage sites
  • Engaging neonatal Fc receptor (FcRn) recycling pathways
  • Eliminating N-linked glycosylation
  • Reducing molecular size below glomerular filtration threshold

Correct Answer: Engaging neonatal Fc receptor (FcRn) recycling pathways

Q20. Which factor is most frequently implicated in aggregation of protein therapeutics during formulation or storage?

  • Excessively high pI causing only crystalline solids
  • Exposure of hydrophobic patches due to partial unfolding
  • Complete absence of secondary structure
  • Presence of too many disulfide bonds always

Correct Answer: Exposure of hydrophobic patches due to partial unfolding

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