Structure-function relations in flavodoxins.

摘要: Flavodoxins are low molecular weight, FMN containing, proteins which function as electron transfer agents in a variety of microbial metabolic processes, including nitrogen fixation. Utilizing structural information obtained from x-ray crystal analysis, it has been possible to derive some new and important insights into the relationships exist between flavin properties protein environment by comparing spectroscopic, thermodynamic kinetic behavior flavodoxins with that free flavin. Thus, for example, qualitative understanding contribution redox potentials, semiquinone reactivity mechanism is beginning emerge. The highly negative potential required biochemical activity accomplished stabilizing via hydrogen bond N-5 position destabilizing fully-reduced form constraining assume an unfavorable planar conformation. lowered aforementioned bond, well interaction tryptophan residue binding site. Electron through exposed dimethylbenzene ring bound coenzyme. Although not at present determine extent this can be generalized other flavoproteins, clear study will provide us least principles biological systems have used modify fulfill need.