Impact of Cysteine to Alanine Substitution on Protein Structure

In a laboratory, researchers are investigating the impact of different amino acids on protein folding and stability. They conduct a series of experiments using a mutant protein, originally composed of 200 amino acids, that contains a critical disulfide bond formed between the thiol groups of cysteine residues. During their study, the researchers replace two cysteine residues at specific positions with alanine residues. This change results in destabilization of the protein structure.

To better understand why the replacement of cysteine with alanine affected protein stability, focus on the properties of the original and modified residues and their role in protein folding. Which of the following statements accurately describes the implications of substituting cysteine residues with alanine with respect to protein structure?