Correlated Motion-Based Residue Network Analysis Reveals the Distal Thermal Activation in Soybean Lipoxygenase

Abstract

Enzyme catalysis has been shown to depend on distal pathways that channel thermal energy from solvent to the active site. In soybean lipoxygenase (SLO), experiments identified a cone-shaped network connecting loop residue Gln322 to Leu546 but not Leu754 in the active site. Here, microsecond molecular dynamics and a correlated motion-based protocol provide an atomistic analysis of such long-range communication. The developed approach enables systematic screening of communication between active site-specific residues that directly contact bound substrate and surface-exposed residues on the protein-solvent interface. In doing so, it provides a deeper molecular insight into experimentally mapped networks by resolving communication trends across diverse conformational ensembles. The simulations recover the experimentally demonstrated thermal initiation loop and the Leu546-directed cone in SLO, exclude the negative-control Ser596, and explain the preference for Leu546 over Leu754 through shorter, more correlated helical pathways. Mutational analysis further reveals the impact of single-site mutations on the network preference between Leu546 and Leu754. These results unify experiments and computation, corroborating an anisotropic channeling of thermal energy in SLO and establishing a general framework for computing distal intra-protein pathways that may enable the thermal activation of enzyme function.