Certain animals make antimicrobial proteins that defend them against pathogens. These proteins could be used to destroy human pathogens, but when they are used as a medicine they are broken down by protein-digesting enzymes. Substituting one of the amino acids in the protein with an amino acid synthesised in the laboratory produced a modified protein that was not broken down. What might account for the fact that this modified protein was not broken down by the protein-digesting enzymes?
- A1, 2 and 3
- B1 and 2 only
- C1 and 3 only
- D2 and 3 only