Hemerythrin-like protein Rv2633c is a small 18 kDa protein that is expressed in Mycobacterium tuberculosis (Mtb). Sequence analysis of Rv2633c predicts the presence of a hemerythrin-like domain, which binds dioxygen using a µ-oxo-bridge (Fe-O-Fe), rather than a heme group. Though it is noticeably upregulated during macrophage infection and during in vitro acidification, the role of Rv2633c in Mtb survival has yet to be elucidated. This project aims to characterize the function of Rv2633c by studying the in vitro response of the recombinant protein to conditions present in the macrophage lysosome, such as reduced oxygen levels or the presence of reactive oxygen species. UV-visible spectroscopy is used to observe these changes, as the spectrum shows a characteristic peak at 330 nm that likely corresponds to the diiron cofactor in its native state. Our results show this spectrum shifts in response to hydrogen peroxide addition, showing the proposed environmental conditions can affect the active site. Bioinformatics techniques, such as the 3D modeling program SWISS-MODEL, have been used to hypothesize possible structure and function. Determining the function of Rv2633c may help explain how Mtb so readily evades the human immune system to reside in the macrophage.