Computational analysis of dimer G6PD structure to elucidate pathogenicity of G6PD variants

Abstract

An inherent genetic enzyme disorder in humans, known as glucose-6-phosphate dehydrogenase (G6PD) deficiency, arises due to specific mutations. While the prevailing approach for investigating G6PD variants involves biochemical analysis, the intricate structural details remain limited, impeding a comprehensive understanding of how different G6PD variants of varying classes impact their functionality. This study 22 examined the dynamic properties of G6PD wild types and six G6PD variants from 23 different classes using molecular dynamic simulation (MDS). The wild-type and variant 24 G6PD structures unveil high fluctuations within the amino acid range of 274e515, the structural NADPþ binding site, pivotal for enzyme dimerization. Specifically, two variants, G6PDZacatecas (R257L) and G6PDDurham (K238R), demonstrate compromised structural stability at the dimer interface, attributable to the disruption of a salt bridge involving Glu 206 and Lys 407, along with the disturbance of hydrogen bonds formed by Asp 421 at the bN-bN sheets. Consequently, this impairment cascades to affect the binding affinity of crucial interactions, such as Lys 171- Glucose-6-Phosphate (G6P) and Lys 171-catalytic NADPþ, leading to diminished enzyme activity. This study underscores the utility of computational in silico techniques in predicting the structural alterations and flexibility of G6PD variants. This insight holds promise for guiding future endeavors in drug development targeted at mitigating the impacts of G6PD deficiency.