Spectrophotometric assays for measuring photorespiratory glutamate: Glyoxylate and serine: Glyoxylate aminotransferase reactions

Authors

• Mair C. Edwards*, Eastern Michigan University
• Aaron H. Liepman, Eastern Michigan University

Document Type

Book Chapter

Publication Date

2024

Department/School

Biology

Publication Title

Photorespiration: Methods and Protocols

Abstract

Glutamate:glyoxylate aminotransferase (GGAT; EC 2.6.1.4) and serine:glyoxylate aminotransferase activities (SGAT; EC 2.6.1.45) are central photorespiratory reactions within plant peroxisomes. Both enzymatic reactions convert glyoxylate, a product of glycolate oxidase, to glycine, a substrate of the mitochondrial glycine decarboxylase complex. The GGAT reaction uses glutamate as an amino group donor and also produces α-ketoglutarate, which is recycled to glutamate in plastids by ferredoxin-dependent glutamate synthase. Using serine, a product of mitochondrial serine hydroxymethyltransferase, as an amino group donor, the SGAT reaction also produces hydroxypyruvate, a substrate of hydroxypyruvate reductase. The activities of these photorespiratory aminotransferases can be measured using indirect, coupled, spectrophotometric assays, detailed herein.

Comments

A. H. Liepman is a faculty member in EMU's Department of Biology.

*M. C. Edwards is an EMU student.

Recommended Citation

Edwards, M. C., & Liepman, A. H. (2024). Spectrophotometric assays for measuring photorespiratory glutamate: Glyoxylate and serine: Glyoxylate aminotransferase reactions. In B. J. Walker (Ed.), Photorespiration: Methods and protocols (Vol. 2792, pp. 41–49). Springer. https://doi.org/10.1007/978-1-0716-3802-6_4