Characterization of Heme Uptake Proteins; HtaB, ChtB, and ChtA from Corynebacterium Diphtheriae Approaches to the Reaction of Dechloromonas Aromatica Chlorite Dismutase with Nitrite

Author

Catherine OdhiamboFollow

Date of Award

8-11-2020

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

First Advisor

Dabney White Dixon

Abstract

Heme is a source of iron for many pathogenic bacteria. Corynebacterium diphtheriae, the first protein in the system is HtaA, ChtA, and/or ChtC; heme is transferred to HtaB or ChtB. Heme is then mobilized into the cytosol by the ABC transporter where iron is released by the heme oxygenase.

Growth and expression temperatures for ChtA were of 37 °C and induction OD₆₀₀ between 0.6 and 0.9. Final IPTG concentration of 0.3 mM. ChtA extinction coefficient is 1.4 x 10⁵ M^-1 cm^-1 at the Soret. ChtA is less stable than HtaA-CR2 to denaturation in guanidinium hydrochloride.

Dechloromonas aromatica chlorite dismutase (DaCld) detoxifies chlorite to chloride and dioxygen. Chlorite sources often have nitrite. The goal is to identify the structure of this adduct.

Temperatures of growth and expression, 30 and 20 °C, respectively, an induction OD₆₀₀ of 0.30, and a final IPTG concentration of 0.1 mM resulted in the desired holo DaCld.

DOI

https://doi.org/10.57709/18780788

Recommended Citation

Odhiambo, Catherine, "Characterization of Heme Uptake Proteins; HtaB, ChtB, and ChtA from Corynebacterium Diphtheriae Approaches to the Reaction of Dechloromonas Aromatica Chlorite Dismutase with Nitrite." Thesis, Georgia State University, 2020.
doi: https://doi.org/10.57709/18780788

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