The π–π stacking interaction between lumiflavin and a number of π-electron-rich molecules has been studied by density functional theory using several new-generation density functionals. Six known lumiflavin-aromatic adducts were used and the models were evaluated by comparing the geometry and energetics with experimental results. The study found that dispersion-corrected and hybrid functionals with larger (>50%) Hartree–Fock exchanges produced superior results in modeling thermodynamic characteristics of these complexes. The functional producing the best energetics for these model systems was used to study the stacking interactions of lumiflavin with biologically relevant aromatic groups. Additionally, the reduction of flavin — in the presence of both a hydride donor and a non-donor π-electronic system was also studied. Weak interactions were observed in the stacked lumiflavin complexes of benzene, phenol, and indole, mimicking phenyl alanine, tryptophan, and tyrosine side chains, respectively, of an enzyme. The stacked complex of naphthalene and flavin showed little change in flavin’s redox potential indicating insignificant effect on the thermodynamics of the hydride transfer reaction. In contrast, the hydride transfer reaction with the hydride donor N-methyl nicotinamide tells a different story, as the transition state was found to be strongly impacted by the stacking interactions. A comparison of performance between the density functional theory (DFT) and the computationally less expensive dispersion-corrected self-consistent density functional tight-binding (SCC-DFTB-D) theory revealed that the latter produces consistent energetics for this hydride transfer reaction and additional DFT-computed perturbative corrections could significantly improve these results.
Written by Sudeep Bhattacharyay
In This Story
- Caitlin Bresnahan
- Clorice Reinhardt
- Thomas Bartholow
- John Rumpel
- Michael North
Departments + Programs
You may also like:
Five research projects in four years
Caitlin Hedberg took student research to new levels while at UW-Eau Claire. She was part of five research projects with three professors. She'll graduate in May with a major in physics, minors in math and linguistics and a certificate in Mandarin Chinese.
CERCA returns in 2021 with virtual platform
The Celebration of Excellence in Research and Creative Activity (CERCA) at the University of Wisconsin-Eau Claire each spring showcases the best in student-faculty/staff collaboration to the university community and beyond.
Research prepares new grad for future success
Katherine Langfield's research presentation took top honors even though other presenters included graduate students. Langfield, who will graduate in May, was one of just five student award winners at the conference.