Answer to Question #260429 in Cell Biology for hayrunisa

Question

A new drug is developed which selectively cleaves covalent bonds between two sulfur atoms of non-adjacent amino acids in a polypeptide chain. Which level of protein structure in affected molecules would be most directly affected by the drug?

a. Secondary structure

b. Primary structure

c. Tertiary structure

d. Quaternary syructure

Answer 1

Among all amino acids, cysteine oxidases from Cystine, where 2 cysteine molecules are linked by covalent bonds to form a disulfide bridge, usually 5 to 6 residues apart.

So, here the new drug is developed which selectively cleaves covalent bonds between two sulfur atoms of non-adjacent amino acids in a polypeptide chain.

The disulfide bridge is on the main interaction stabilizing the Tertiary structure. Hence, this drug Impact the tertiary and quaternary structure (as present in Insulin).