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 …

Investigation Of Proline Utilization A: Kinetic Analysis Of Substrate Channel-Blocking Mutants And Creation Of A Trifunctional Chimera Enzyme, Benjamin W. Arentson

Department of Biochemistry: Dissertations, Theses, and Student Research

Proline metabolism is known to be involved in many cellular processes such as cell signaling, cellular redox balance, and cell survival. One of the enzymes involved in proline catabolism, proline utilization A, plays a role in oxidizing proline to glutamate in a two-step oxidation pathway involving enzymes proline dehydrogenase (PRODH) and Δ¹-pyrroline-5-carboxylate dehydrogenase (P5CDH).

Intermediate P5C/GSA has been shown to use an intramolecular channel to move from the PRODH active site to the P5CDH active site in a phenomenon called substrate channeling. In this work, one of the main objectives was to learn more about the channel usage. …