Biochemistry, Biophysics, and Structural Biology Commons^™

Characterization Of The Multifunctional Enzyme Proline Utilization A, Yizi Mao

Department of Biochemistry: Dissertations, Theses, and Student Research

Proline is a unique and important amino acid. Proline is a proteogenic amino acid and its metabolism is involved in many critical cellular functions. Therefore, proline metabolism is tightly regulated, and dysfunction of proline metabolism is related to human diseases. The first step of proline oxidization to ∆¹-pyrroline-5-carboxylic acid (P5C) is catalyzed by proline dehydrogenase (PRODH). P5C is then non-enzymatically hydrolyzed to glutamate-γ-semialdehyde (GSA), which can be further oxidized to glutamate by P5C dehydrogenase (P5CDH/GSALDH). In Gram-negative bacteria, the PRODH and P5CDH enzymes are expressed as one polypeptide called proline utilization A (PutA). In some Gram-negative bacteria an …

Mitochondrial Metal Homeostasis: A Look Into Iron And Copper Mobilization Within Mitochondria, Jonathan Dietz

Department of Biochemistry: Dissertations, Theses, and Student Research

Cellular iron and copper homeostasis is interdependent with mitochondrial iron and copper homeostasis. Mitochondria must import iron to form iron-sulfur clusters and heme, while it must import copper for usage and storage. These cofactors are incorporated into mitochondrial proteins that support essential functions, including cellular respiration and maintaining redox homeostasis. In turn, mitochondria also provide heme to the cell and enables the biogenesis of cytosolic iron-sulfur cluster containing proteins, while also providing copper when needed. Due to both metals (and their modified species) reactivity, iron and copper are stored and trafficked within the mitochondria carefully. Although these cofactors are crucial …

Development Of High Value Oil Traits Using The Model Oilseed Crop Camelina Sativa, Evan Updike

Department of Biochemistry: Dissertations, Theses, and Student Research

Plant oils are an important source of food, fuel, and feed in our society today. The oil found in the seeds of plants is composed almost entirely of triacylglycerol (TAG) molecules, which consist of three fatty acids esterified to a glycerol backbone. As crude oil supplies decline, vegetable oils are gaining traction as a renewable substitute to petroleum-based materials in fuels, lubricants, and specialty oleochemicals. However, as it currently stands vegetable oils do not possess the properties necessary to fill the void of a petroleum free world.

To address this problem, plant biotechnologists have done extensive work on genetic engineering …

Characterization Of Sphingolipid Biosynthesis And Modification In Plants, Dongdong Zhang

Department of Biochemistry: Dissertations, Theses, and Student Research

Sphingolipids are ubiquitous membrane lipids in eukaryotic cells. Ceramides, the backbone of sphingolipids, are synthesized by ceramide synthases (CerSs), which form amide bonds between long-chain bases (LCBs) and the acyl groups of acyl-CoAs. Class I CerS works predominantly towards C16-CoA, whereas Class II CerS works towards C24-CoA. Plant sphingolipids generally have 16-carbon and 24-carbon as the major acyl groups. However, the sphingolipids of Oryza sativa and Zea mays have 20-carbon and 24-carbon as the predominant acyl groups. This dissertation aims to understand the substrate preference of CerSs in monocots such as rice. Phylogenetic analysis shows the Class I CerSs from …