Purification and Kinetic Analysis of Rhodospirillum Centenum Lov-Kinase and Its Putative Response Regulator
Publisher
The University of Arizona.Rights
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.Abstract
LOV histidine kinase (LOV-HK) from the purple photosynthetic bacterium Rhodospirillum centenum was expressed and characterized along with its putative response regulator (RR). LOV-HK and RR were expressed in E. coli and purified in a two-step process of nickel affinity chromatography followed by gel filtration chromatography. Mass spectrometry showed that both proteins were successfully expressed. The LOV-HK dark-state spectrum has broad peaks at 362nm and 450nm characteristic of the flavin mononucleotide (FMN) chromophore in a tight binding pocket. The light-state spectrum showed ~33% bleach at 450nm, which slowly returned to the dark state. The recovery of LOV-HK had a rate constant of 4.13 x 10⁻⁴ S⁻¹ with a half-life of 28.0min. The recovery of LOV-HK was also investigated in the presence of RR and showed a rate of 4.17x 10⁻⁴ S⁻¹ (half-life of 27.7min). These results do not conclusively demonstrate an interaction between the two proteins, however further study is warranted.Type
textElectronic Thesis
Degree Name
B.S.Degree Level
bachelorsDegree Program
Honors CollegeBiochemistry and Molecular Biophysics