What is the primary function of peptidyl-prolyl cis-trans isomerase in protein metabolism?

A To catalyze the hydrolysis of peptide bonds
B To facilitate the folding of proteins by isomerizing proline residues ✓
C To inhibit the activity of proteases
D To synthesize new peptide bonds

Explanation

Peptidyl-prolyl cis-trans isomerase is an enzyme that assists in the folding of proteins by catalyzing the cis-trans isomerization of proline residues, which is essential for the proper conformation of many proteins.

Source

Alberts et al., Molecular Biology of the Cell
Protein Metabolism Biochemistry Protein Folding Medium MEDICAL Confidence: high