Insights on the dynamic behavior of protein disulfide isomerase in the solution environment through the SAXS technique

In Silico Pharmacol. 2024 Apr 5;12(1):23. doi: 10.1007/s40203-024-00198-0. eCollection 2024.

Abstract

The dynamic behavior of Protein Disulfide Isomerase (PDI) in an aqueous solution environment under physiologically active pH has been experimentally verified in this study using Small Angle X-ray Scattering (SAXS) technique. The structural mechanism of dimerization for full-length PDI molecules and co-complex with two renowned substrates has been comprehensively discussed. The structure models obtained from the SAXS data of PDI purified from bovine liver display behavior duality between unaccompanied-enzyme and after engaged with substrates. The analysis of SAXS data revealed that PDI exists as a homo-dimer in the solution environment, and substrate induction provoked its segregation into monomer to enable the enzyme to interact systematically with incoming clients.

Supplementary information: The online version contains supplementary material available at 10.1007/s40203-024-00198-0.

Keywords: Ab-initio modeling; Bovine pancreatic trypsin inhibitor; Ensemble Optimization Method; Protein Disulfide Isomerase; Ribonuclease; Small-angle X-ray scattering.