Sponsor
Chemistry
Defense: Natalie Schulte- The Biophysical Characterization of Extracellular and Intracellular Metal Binding and Transport Proteins in Mammalian and Bacterial Systems
Friday, June 6,
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Speaker(s): Natalie Schulte
Defense: Natalie Schulte
The Biophysical Characterization of Extracellular and Intracellular Metal Binding and Transport Proteins in Mammalian and Bacterial Systems
Metals like copper and zinc play an essential role in cellular function such as enzyme cofactors, methods of electron transport, metabolic oxidation, and protein structure. However, essential metals are delicately balanced in systems to maintain homeostasis, as too much metal can have detrimental effects including oxidative stress and protein aggregation that causes cells to die. Copper is particularly interesting because it can exist and cycle through multiple oxidation states, Cu+ and Cu2+, within biological systems. This metal homeostasis is not only essential to the intracellular environment but exists in the extracellular space as well with proteins like human serum albumin and mucin glycoproteins helping to regulate metals being transported to cells for uptake. The goal of this work was to characterize metal binding, ternary complex formation, and transport of extracellular and intracellular mammalian and bacterial proteins to better understand metal homeostasis. To do this, extracellular proteins human serum albumin and a segment of an intestinal mucin glycoprotein, MUC2 D1, were investigated for their abilities to transport Cu+ to a model of the cellular copper importer Ctr1 and to simultaneously bind Cu+ and Cu2+ to begin to understand the intestinal protein's role in copper homeostasis, respectively. Additionally, intracellular bacterial glyceraldehyde-3-phosphate dehydrogenase was studied to investigate the impact of cellular copper stress on function, and periplasmic New-Delhi metallo-beta-lactamase-1 was used as a model protein to understand the propensity of ternary complexes to form with commonly used fluorescent indicators and zinc. This conglomeration of extracellular and intracellular biophysical characterization shows for the first time the ability of human serum albumin to bind and transport Cu+ to a model peptide of Ctr1, MUC2 D1 to simultaneously bind multiple oxidation states of copper, and the oxidative stress that can occur to glyceraldehyde-3-phosphate dehydrogenase under copper stress and the natural defenses the cell can take to recover the damage.
The Biophysical Characterization of Extracellular and Intracellular Metal Binding and Transport Proteins in Mammalian and Bacterial Systems
Metals like copper and zinc play an essential role in cellular function such as enzyme cofactors, methods of electron transport, metabolic oxidation, and protein structure. However, essential metals are delicately balanced in systems to maintain homeostasis, as too much metal can have detrimental effects including oxidative stress and protein aggregation that causes cells to die. Copper is particularly interesting because it can exist and cycle through multiple oxidation states, Cu+ and Cu2+, within biological systems. This metal homeostasis is not only essential to the intracellular environment but exists in the extracellular space as well with proteins like human serum albumin and mucin glycoproteins helping to regulate metals being transported to cells for uptake. The goal of this work was to characterize metal binding, ternary complex formation, and transport of extracellular and intracellular mammalian and bacterial proteins to better understand metal homeostasis. To do this, extracellular proteins human serum albumin and a segment of an intestinal mucin glycoprotein, MUC2 D1, were investigated for their abilities to transport Cu+ to a model of the cellular copper importer Ctr1 and to simultaneously bind Cu+ and Cu2+ to begin to understand the intestinal protein's role in copper homeostasis, respectively. Additionally, intracellular bacterial glyceraldehyde-3-phosphate dehydrogenase was studied to investigate the impact of cellular copper stress on function, and periplasmic New-Delhi metallo-beta-lactamase-1 was used as a model protein to understand the propensity of ternary complexes to form with commonly used fluorescent indicators and zinc. This conglomeration of extracellular and intracellular biophysical characterization shows for the first time the ability of human serum albumin to bind and transport Cu+ to a model peptide of Ctr1, MUC2 D1 to simultaneously bind multiple oxidation states of copper, and the oxidative stress that can occur to glyceraldehyde-3-phosphate dehydrogenase under copper stress and the natural defenses the cell can take to recover the damage.
