Biomimetic Environment to Study E. coli Complex I through Surface-Enhanced IR Absorption Spectroscopy.

Biochemistry

PubMedID: 25225967

Kriegel S, Uchida T, Osawa M, Friedrich T, Hellwig P. Biomimetic Environment to Study E. coli Complex I through Surface-Enhanced IR Absorption Spectroscopy. Biochemistry. 2014;53(40):6340-7.
In this study complex I was immobilized in a biomimetic environment on a gold layer deposited on an ATR-crystal in order to functionally probe the enzyme against substrates and inhibitors via surface-enhanced IR absorption spectroscopy (SEIRAS) and cyclic voltammetry (CV). To achieve this immobilization, two methods based on the generation of a high affinity self-assembled monolayer (SAM) were probed. The first made use of the affinity of Ni-NTA toward a hexahistidine tag that was genetically engineered onto complex I and the second exploited the affinity of the enzyme toward its natural substrate NADH. Experiments were also performed with complex I reconstituted in lipids. Both approaches have been found to be successful, and electrochemically induced IR difference spectra of complex I were obtained.