Biochemical Analysis of Two Single Mutants that Give Rise to a Polymorphic G6PD A-Double Mutant

• Published in: International journal of molecular sciences Vol. 18; no. 11; p. 2244
• Main Authors: Ramírez-Nava, Edson Jiovany, Ortega-Cuellar, Daniel, Serrano-Posada, Hugo, González-Valdez, Abigail, Vanoye-Carlo, America, Hernández-Ochoa, Beatriz, Sierra-Palacios, Edgar, Hernández-Pineda, Jessica, Rodríguez-Bustamante, Eduardo, Arreguin-Espinosa, Roberto, Oria-Hernández, Jesús, Reyes-Vivas, Horacio, Marcial-Quino, Jaime, Gómez-Manzo, Saúl
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 26.10.2017; MDPI
• Subjects: Anemia; Biochemical analysis; Biochemistry; Catalysis; Catalytic activity; Enzymes; G6PD deficiency; Gene expression; Glucose 6 phosphate dehydrogenase; Glucosephosphate dehydrogenase; Hemolytic anemia; kinetic parameters; Mutation; Structural stability; Structure-function relationships; thermal stability; kinetic parameters; thermal stability; G6PD deficiency
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms18112244

Glucose-6-phosphate dehydrogenase (G6PD) is a key regulatory enzyme that plays a crucial role in the regulation of cellular energy and redox balance. Mutations in the gene encoding G6PD cause the most common enzymopathy that drives hereditary nonspherocytic hemolytic anemia. To gain insights into the effects of mutations in G6PD enzyme efficiency, we have investigated the biochemical, kinetic, and structural changes of three clinical G6PD variants, the single mutations G6PD A+ (Asn126AspD) and G6PD Nefza (Leu323Pro), and the double mutant G6PD A- (Asn126Asp + Leu323Pro). The mutants showed lower residual activity (≤50% of WT G6PD) and displayed important kinetic changes. Although all Class III mutants were located in different regions of the three-dimensional structure of the enzyme and were not close to the active site, these mutants had a deleterious effect over catalytic activity and structural stability. The results indicated that the G6PD Nefza mutation was mainly responsible for the functional and structural alterations observed in the double mutant G6PD A-. Moreover, our study suggests that the G6PD Nefza and G6PD A- mutations affect enzyme functions in a similar fashion to those reported for Class I mutations.